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W3C

Techniques for WCAG 2.0

Editor's Draft 27 April 2006

This version:
http://www.w3.org/WAI/GL/WCAG20/WD-WCAG20-TECHS-20060427/
Latest version:
http://www.w3.org/WAI/GL/WCAG20/WD-WCAG20-TECHS/
Editors:
Ben Caldwell, Trace Research & Development Center, University of Wisconsin-Madison
Wendy Chisholm, W3C
John Slatin, Accessibility Institute, University of Texas at Austin
Gregg Vanderheiden, Trace Research & Development Center, University of Wisconsin-Madison

Abstract

This document provides information to Web content developers who wish to satisfy the success criteria of "Web Content Accessibility Guidelines 2.0" [WCAG20] . General Techniques in this document are applicable to all technologies while HTML, CSS, Scripting, and SMIL techniques apply only to those technologies.

Use of the techniques provided in this document makes it easier for Web content to demonstrate conformance to WCAG 2.0 success criteria than if these techniques are not used.

There may be other techniques besides those provided in this document that may be used to demonstrate conformance to WCAG 2.0; in that case, submission of the techniques to the WCAG WG is encouraged so they can be considered for inclusion in this document, so that the set of techniques maintained by the WCAG WG is as comprehensive as possible. Please submit techniques for consideration using the "Techniques Submission Form."

This document is part of a series of documents published by the W3C Web Accessibility Initiative (WAI) to support WCAG 2.0.

Status of this Document

This document is for review by the WCAG WG and is subject to change without notice. This document has no formal standing within W3C. Please consult the group's home page and the W3C technical reports index for information about the latest publications by this group.

This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at http://www.w3.org/TR/.

This is a First Public Working Draft of Techniques for WCAG 2.0. It is the first publication as a combined document; previously, techniques were published as separate documents - one for each technology. This document is being published as WCAG 2.0 goes to Last Call. It provides explanation of the techniques documented by the Web Content Accessibility Guidelines Working Group. Some are sufficient to meet a particular success criterion (either by themselves or in combination with other techniques) while other techniques are advisory and optional. None of the techniques are required to meet WCAG 2.0 although some may be the only known method if a particular technology is used.

The Working Group encourages review and comments on this document, in particular: is the format of the techniques clear? is the information useful? is the relationship to the normative document (WCAG 2.0) clear? Your comments on this Working Draft will help the WCAG Working Group improve the document before it is published as a Working Group Note when WCAG 2.0 becomes a W3C Recommendation.

Comments on this working draft are due on or before 31 May, 2006. To comment, please use one of the following standard response formats.

Instructions and downloads for all are available at http:///www.w3.org/WAI/WCAG20/comments/. Please send completed forms to public-comments-wcag20@w3.org.

The archives for the public comments list are publicly available. Archives of the WCAG WG mailing list discussions are also publicly available.

Please refer to Issue tracking for WCAG 2.0 Techniques for a list of open issues related to this Working Draft. The History of Changes to Techniques for WCAG 2.0 Working Drafts is also available.

Publication as a Working Draft does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.

This document has been produced as part of the W3C Web Accessibility Initiative (WAI). The goals of the WCAG Working Group are discussed in the WCAG Working Group charter. The WCAG Working Group is part of the WAI Technical Activity.

This document was produced by a group operating under the 5 February 2004 W3C Patent Policy. The group does not expect this document to become a W3C Recommendation. This document is informative only. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.

This document was produced by a group operating under the 5 February 2004 W3C Patent Policy. The group does not expect this document to become a W3C Recommendation. This document is informative only. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.


Table of Contents

Appendix


1. Common Failures


F1: Failure of SC 1.3.3 due to changing the meaning of content by positioning information with CSS

Applicability

All technologies that support CSS.

This technique is referenced from:

Description

This describes the failure condition that results when CSS, rather than structural markup, is used to modify the visual layout of the content, and the modified layout changes the meaning of the content. Using the positioning properties of CSS2, content may be displayed at any position on the user's viewport. The order in which items appear on a screen may be different than the order they are found in the source document. Assistive technologies rely on the source code or other programmatically determined order to render the content in the correct sequence. Thus, it is important not to rely on CSS for a visual-only layout which differs from the source code or programmatically determined reading order.

Examples

Failure Example 1

The following example demonstrates how CSS has been improperly used to create a set of columns. In addition, the text appears visually in the browser in a different order than in the markup.

In this example a class is defined for each object that is being positioned. When style sheets are applied, the text appears in two columns. Elements of class "menu1" (Products) and "menu2" (Locations) appear as column headings. "Telephones, Computers, and Portable MP3 Players" are listed under Products and "Idaho" and "Wisconsin" are listed under Locations (note the different order for Idaho and Wisconsin in the source code order).

Since appropriate structural elements have not been used, when style sheets are not applied, all of the text appears in one line in the source order, "Products Locations Telephones Computers Portable MP3 Players Wisconsin Idaho."

Here is the HTML content:

<div class="box">      
     <span class="menu1">Products</span>       
     <span class="menu2">Locations</span>       
     <span class="item1">Telephones</span>       
     <span class="item2">Computers</span>       
     <span class="item3">Portable MP3 Players</span>       
     <span class="item5">Wisconsin</span>       
     <span class="item4">Idaho</span>
</div>

Here are the styles for the above content:

.menu1 { 
     position: absolute; 
     top: 3em; 
     left: 0em;     
     margin: 0px; 
     font-family: sans-serif;     
     font-size: 120%; 
     color: red; 
     background-color: white 
}        
.menu2 { 
     position: absolute; 
     top: 3em; 
     left: 10em;     
     margin: 0px; 
     font-family: sans-serif;     
     font-size: 120%; 
     color: red; 
     background-color: white 
}      
.item1 { 
     position: absolute; 
     top: 7em; 
     left: 0em; 
     margin: 0px 
}      
.item2 { 
     position: absolute; 
     top: 8em; 
     left: 0em; 
     margin: 0px 
}      
.item3 { 
     position: absolute; 
     top: 9em; 
     left: 0em; 
     margin: 0px 
}      
.item4 { 
     position: absolute; 
     top: 7em; 
     left: 14em; 
     margin: 0px 
}      
.item5 { 
     position: absolute; 
     top: 8em; left: 14em; 
     margin: 0px 
}      
#box { 
     position: absolute; 
     top: 5em; 
     left: 5em 
} 

A better solution for this content would be to use more meaningful elements, such as a table or a definition list.

Resources

No resources available for this technique.

Tests

Procedure

For content which uses CSS for positioning:

  1. Remove the style information from the document or turn off use of style sheets in the user agent.

  2. Check that the reading order of the content is correct and the meaning of the content is preserved.

Expected Results
  • If step #2 is false, then this failure condition applies and the content fails this success criterion.


F2: Failure of SC 1.3.1 and 1.3.4 due to using CSS to create variations in presentation of text that conveys information without also using the appropriate markup or text

Applicability

All technologies that support CSS.

This technique is referenced from:

Description

It is a failure to use CSS to style text to convey information instead of conveying the information by using the appropriate markup or text. An HTML example is to use CSS to style text in bold for emphasis rather than using the strong element.

Examples

Failure Example 1: Emphasis in written dialogue.

Here is a CSS class to specify bold.

 .yell {
   font-weight:bold;
 }

The following example fails because the information conveyed by using the CSS font-weight property to change to a bold font is not conveyed through semantic markup or stated explicitly in the text.

<p>
 &quot;I said, <span class="yell">NO</span>, not before dinner!&quot;, 
 was the exasperated response when Timmy asked his mother for the 
 fourth time for an ice cream cone. 
</p>

Resources

No resources available for this technique.

Tests

Procedure
  1. Find visually styled elements on the page that convey information.

  2. Check that the appropriate semantics of the technology are used and that the information is not conveyed only by variations in presentation through CSS.

Expected Results
  • If step #2 is false, then this failure condition applies and the content fails this success criterion.


F3: Failure of SC 1.1.1 due to using CSS to include images that convey important information

Applicability

All technologies that support CSS.

This technique is referenced from:

Description

The CSS background-image property provides a way to include images in the document with CSS without any reference in the HTML code. The CSS background-image property was designed for decorative purposes and it is not possible to associate text alternatives with images that are included via CSS. Text alternatives are necessary for people who cannot see images that convey important information. Therefore, it is a failure to use this property to add images to convey important information.

Examples

Failure Example 1:

In the following example, part of the content is contained in an image that is presented by CSS alone. In this example, the image TopRate.png is a 180 by 200 pixel image that contains the text, "19.3% APR Typical Variable."

 The CSS contains: 
p#bestinterest {
  padding-left: 200px;
  background: transparent url(/images/TopRate.png) no-repeat top left;
}

It is used in this excerpt:

 
<p id="bestinterest">
  Where else would you find a better interest rate?
</p>
Failure Example 2:

A book distributor uses background images to provide icons against a list of book titles to indicate whether they are new, limited, in-stock, or out of stock.

The CSS contains:

ul#booklist li {
  padding-left: 20px;
}

ul#booklist li.new {
  background: transparent url(new.png) no-repeat top left; 
}
                            
ul#booklist li.limited {
  background: transparent url(limited.png) no-repeat top left; 
}
                            
ul#booklist li.instock {
  background: transparent url(instock.png) no-repeat top left; 
}

ul#booklist li.outstock {
  background: transparent url(outstock.png) no-repeat top left; 
}

It is used in this excerpt:

<ul id="booklist">
  <li class="new">Some book</li>
  <li class="instock">Some other book</li>
  <li class="limited">A book we desperately want to get rid of</li>
  ...
  <li class="outstock">A book you actually want </li>
</ul>

Resources

No resources available for this technique.

Tests

Procedure
  1. Examine all images added to the content via CSS.

  2. Check that the images do not convey important information.

Expected Results
  • Step #2. If it is true then this failure condition applies and content fails the success criterion.


F4: Failure of SC 2.2.2 due to using text-decoration:blink without a mechanism to stop it in less than three seconds

Applicability

Cascading Style Sheets.

This technique is referenced from:

User Agent and Assistive Technology Support Notes

The blink value of the text-decoration property is not supported by Internet Explorer. It is supported in Netscape/Mozilla family browsers. Not tested in others (e.g., Safari, Opera).

Description

CSS defines the blink value for the text-decoration property. When used, it causes any text in elements with this property to blink at a predetermined rate. This cannot be interrupted by the user, nor can it be disabled as a user agent preference. The blinking continues as long as the page is displayed. Therefore, content that uses text-decoration:blink fails the success criterion because blinking can continue for more than three seconds.

Examples

Failure Example 1

A product list page uses the text-decoration:blink style on an element to draw attention to sale prices. This fails the success criterion because users cannot control the blink.

<p>My Great Product <span style="text-decoration:blink">Sale! $44,995!</span></p>

Resources

Tests

Procedure
  1. Examine inline styles, internal stylesheets, and external stylesheets for the text-decoration property with a value of "blink".

  2. If the property is used, determine if the ID, class, or element identified by selectors on which this property is defined are used in the document.

Expected Results
  • If step #1 and step #2 are true, the content fails the success criterion.


F5: Failure of SC 3.1.1 due to using CSS styling to control directionality in XHTML/HTML

Applicability

(X)HTML documents that use CSS

This technique is referenced from:

User Agent and Assistive Technology Support Notes

Description

This describes a failure condition for (X)HTML documents that specify a text direction by using CSS styling, rather than using bidirectional markup. CSS provides support for text direction via the unicode-bidi and direction properties.

Because directionality is an integral part of the document structure, markup should be used to set the directionality for a document or chunk of information, or to identify places in the text where the Unicode bidirectional algorithm alone is insufficient to achieve desired directionality. Styling applied by CSS is not permanent. It may be turned off, be overridden, go unrecognised, or be changed/replaced in different contexts. Although bidirectional markup is only needed for the visual rendering of text, it is not purely decorative in function.

Examples

Failure Example 1

A style sheet setting the writing direction:

/* Rules for bidi */
HEBREW, HE-QUO  {direction: rtl; unicode-bidi: embed}
ENGLISH         {direction: ltr; unicode-bidi: embed} 
/* Rules for presentation */
HEBREW, ENGLISH, PAR  {display: block}
EMPH                  {font-weight: bold}

Resources

Tests

Procedure
  1. Remove the style information from the document or turn off use of style sheets in the user agent.

  2. Check that the text direction is correct.

Expected Results
  • If step #2 is false, then this failure condition applies and the content fails the success criterion.


F7: Failure of SC 2.2.2 due to an object or applet, such as Java or Flash, that has blinking content without a mechanism to pause the content that blinks for more than three seconds

Applicability

Technologies that support blinking content within an object, applet, or a plug-in.

This technique is referenced from:

Description

When content that is rendered by a plug-in or contained in an applet blinks, there may be no way for the user agent to pause the blinking. If neither the plug-in, applet, nor the content itself provides a mechanism to pause the content, the user may not have sufficient time to read the content between blinks or it may be so distracting that the user will not be able to read other content on the page.

Examples

  • An applet displays an advertisement on a news site. The applet blinks key words in the advertisement in order to call the user's attention to it. The blinking cannot be paused through any user agent settings and the applet does not provide a mechanism to stop it.

Tests

Procedure

For each page that has blinking content in a plugin or applet:

  1. Determine if the content continues to blink for longer than 3 seconds.

  2. Determine if there is a means to pause the blinking content.

Expected Results
  • If step #1 is true and step #2 is false, the content fails the success criterion.


F8: Failure of SC 1.2.1 due to captions omitting some dialogue or important sound effects

Applicability

Applies to all technologies.

This technique is referenced from:

Description

This describes a failure condition for all techniques involving captions. If the "caption" does not include all of the dialog (either verbatim or in essence) as well as all important sounds then the 'Captions' are not real captions.

NOTE: Captions sometimes simplify the spoken text both to make it easier to read and to avoid forcing the viewer to read at very high speed. This is standard procedure and does not invalidate a caption.

Examples

Failure Example 1

Examples of text streams that are not captions include:

  • subtitles that do not include important sounds

  • text that omits dialog during portions of the material

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure
  1. View the material with captioning turned on.

  2. Check that all dialog is accompanied by a caption.

  3. Check that all important sounds are captioned.

Expected Results
  • Step #2 and step #3 are true.


F9: Failure of SC 3.2.5 due to changing the context when the user removes focus from a form element

Applicability

General.

This technique is referenced from:

Description

This document describes a failure that occurs when removing focus from a form element, such as by moving to the next element, causes a change of context.

Examples

Failure Example 1:

The user is going through the form filling out the fields in order. When he moves from the third field to the forth, the form submits.

Resources

Tests

Procedure
  1. Find all form elements.

  2. Go through them in order.

  3. Check if the form submits when you move from one field to the next.

  4. Check if moving from one field to the next launches any new windows.

  5. Check if moving from one filed to the next navigates to another screen.

Expected Results
  • If step #3, step #4, or step #5 is true, then this failure condition applies and the content fails the success criterion.


F10: Failure of SC 2.1.1 due to combining multiple content formats in a way that traps users inside one format type

Applicability

Applies when content creates a situation where the user can enter the content using the keyboard, but can not exit the content using the keyboard.

User Agent and Assistive Technology Support Notes

  • None listed.

This technique is referenced from:

Description

When content includes multiple formats, one or more user agents or plug-ins are often needed in order to successfully present the content to users. For example, a page that includes (X)HTML, SVG, SMIL and XForms may require a browser to load as many as three different plug-ins in order for a user to successfully interact with the content. Some plug-ins create a common situation in which the keyboard focus can become "stuck" in inaccessible plug-ins, leaving a keyboard-only user with no way to return to the accessible content.

Examples

  • A plug-in traps the user A user tabs into a plug-in and is unable to return to content outside the plug-in content with the keyboard. The user has to restart their browser in order to regain control and navigate to a new page and is unable to access any content that appears beyond the plug-in content.

Resources

No resources available for this technique.

Tests

Procedure
  1. Using a keyboard, navigate through the content.

  2. Check to see that the keyboard focus is not "trapped" and it is possible to move keyboard focus out of the plug-in content without closing the user agent or restarting the system.

Expected Results
  • If the keyboard focus becomes "trapped," then this failure condition applies and content fails the success criterion.


F12: Failure of SC 2.2.6 due to having a session time-out without a mechanism for saving user's input and re-establishing that information upon re-authentication

Applicability

Sites that require user login to submit input and that terminate the session after a some period of inactivity.

This technique is referenced from:

Description

Web servers that require user authentication usually have a session mechanism in which a session times out after a period of inactivity from the user. This is sometimes done for security reasons, to protect users who are assumed to have left their computer exposed in a state where someone could do something harmful to them such as transfer bank funds or make an unauthorized purchase. A user with a disability may actually still be working to complete the form as it may take him or her longer to complete the form than would normally be expected. Upon re-authentication, if the state of the user's session is not restored, including all data that had been previously entered into the form, he or she will have to start over. And for these users, it is likely that the session will time out again before they can complete the form. This sets up a situation where a user who needs more time to complete the form can never complete it.

Examples

  • A user submits a form on an authenticated site after their login has expired. On submitting the form, they are prompted to log in again, and then taken to a general welcome page. The data is not processed and they must try again.

  • A user submits a form on an authenticated site after their login has expired. On submitting the form, they are prompted to log in again, and then taken back to the page they were on just before the login, which in this case contains the form they attempted to submit. However, the form is not populated with the data they just entered, and they must re-enter it.

Tests

Procedure

On a site where authentication is required, user input is collected, and which ends the user's session after a known period of inactivity:

  1. Provide user input as required but allow the session to time out, then submit the form.

  2. When requested, re-authenticate with the server.

  3. Determine if the function is performed using the previously submitted data.

Expected Results
  • If step #3 is false, the site fails the success criterion.


F13: Failure of SC 1.3.2 due to having a text alternative that does not include information that is conveyed by color in the image

Applicability

All technologies.

This technique is referenced from:

Description

This objective of this technique is to describe the failure that occurs when an image uses color to convey information, but the text alternative for the image does not convey that information. This can cause problems for people who are blind or colorblind because they will not be able to perceive the information conveyed by the color.

Examples

  • A bar chart of sales data is provided as an image. The chart includes yearly sales figures for four employees in the Sales Department. The text alternative for the image says, "The following bar chart displays the yearly sales figures for the Sales Department. Mary sold 3.1 Million; Fred, 2.6 Million; Bob, 2.2 Million; and Andrew, 3.4 Million. The red bars indicate sales that were below the yearly quota". This text alternative fails to provide the information which is conveyed by the color red in the image. The alternative should indicate which people did not meet the sales quota rather than relying on color.

Resources

No resources available for this technique.

Tests

Procedure

For all images in the content that convey information by way of color :

  1. Check that the information conveyed by color is not included in the text alternative for the image.

Expected Results
  • If step #1 is true, then this failure condition applies and content fails the success criterion.


F14: Failure of SC 1.3.5 due to identifying content only by its shape or location

Applicability

All technologies.

This technique is referenced from:

Description

The objective of this technique is to show how identifying content only by its shape or location makes content difficult to understand and operate. When only visual identification or location is used, users with visual disabilities may find it difficult to locate content since they cannot see the screen or may perceive only a small portion of the screen at one time. Also, location of content can vary if page layout varies due to variations in font, window, or screen size.

Examples

  • A user is completing an on-line survey. There are three buttons at the bottom of the survey form. The instructions state, "Press the square button to exit the survey without saving, Press the triangle button to save in-progress survey results. You may return later to complete the survey. Press the round button to submit the survey results." A screen reader user cannot determine which button is square, triangular, or round. The buttons must have additional information to indicate their functions.

  • A user is reading a news article in an on-line newspaper. The article contains an illustration and additional links for more information. Within the text of the article is a statement, "Please see sidebar to the left of the illustration for links to additional information." An assistive technology user would have difficulty finding the illustration and the sidebar. Some alternatives would be to include the list of links within the text; to provide an in-page link within the text which links to the sidebar; to provide a heading for the sidebar which can be used for navigation and refer to the heading in the instructions.

  • The navigation instructions for a site state, "To go to next page, press the button to the right. To go back to previous page, press the button to the left."

Resources

No resources available for this technique.

Tests

Procedure
  1. Examine the Web unit for textual references to content within the Web unit.

  2. Check that the references do not rely on only the shape or location of the content.

Expected Results
  • If step #2 is false, then this failure condition applies and the content fails this success criterion.


F15: Failure of SC 4.1.2 due to implementing custom controls that do not use an accessibility API for the technology, or do so incompletely

Applicability

Applies to all technologies that support an accessibility API.

This technique is referenced from:

Description

When standard controls from accessible technologies are used, they usually are programmed in a way that uses and supports the accessibility API. If custom controls are created, however, then it is up to the programmer to be sure that the newly created control supports the accessibility API. If this is not done, then assistive technologies will not be able to understand what the control is or how to operate it or may not even know of its existence.

Examples

Failure Example 1

A music player is designed with custom controls that look like musical notes that are stretched for volume, tone etc. The programmer does not make the new control support the Accessibility API. As a result - the controls cannot be identified or controlled from AT.

Resources

(none currently listed)

Tests

Procedure
  1. Using the accessibility checker for the technology (or if that is not available, inspect the code or test with an assistive technology), check the controls to see if they support the accessibility API.

Expected Results
  • If step #1 is false, then this failure condition applies and the content fails this success criterion


F16: Failure of SC 2.2.3 due to including scrolling content where there is not a mechanism to pause and restart the content

Applicability

All technologies that support visual movement or scrolling.

This technique is referenced from:

Description

In this failure technique, there is moving or scrolling content that cannot be paused and resumed by users. In this case, some users with low vision or cognitive disabilities will not be able to perceive the content.

Examples

  • A page has a scrolling news ticker without a mechanism to pause it. Some users are unable to read the scrolling content.

Tests

Procedure

On a page with moving or scrolling content,

  1. Check that a mechanism is provided in the Web unit or user agent to pause moving or scrolling content.

  2. Use the pause mechanism to pause the moving or scrolling content.

  3. Check that the moving or scrolling has stopped and does not restart by itself.

  4. Check that a mechanism is provided in the Web unit or user agent to restart the paused content.

  5. Use the restart mechanism provided to restart the moving content.

  6. Check that the movement or scrolling has resumed from the point where it was stopped.

Expected Results
  • If steps step #1, step #3, step #4, or step #6 are false, then the content fails the success criterion.


F17: Failure of SC 4.1.1 due to insufficient information in DOM to determine one-to-one relationships (e.g., between labels with same id) in HTML

Applicability

Applies to the Document Object Model (DOM) for HTML 4.01 and XHTML 1.x.

This technique is referenced from:

Description

The objective of this technique is to ensure that Web pages can be interpreted consistently by user agents, including assistive technology. If it is ambiguous, different user agents including assistive technologies could present different information to their users. Users of assistive technology for example may have different information presented to them than users of other mainstream user agents. Some elements and attributes in markup languages are required to have unique values, and if this requirement is not honored, the result can be irregular or not uniquely resolvable content. For example, when id attribute values are not unique, they are particularly problematic when referenced by labels, headers in data tables, or used as fragment identifiers, as user agents do not have enough information to provide determine essential relationships (i.e. to determine which label goes with which item).

Examples

Failure Example 1
  • A label element whose for attribute value is an idref that points to a non-existent id

  • An id attribute value that is not unique.

  • An accesskey attribute value that is not unique

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure
  1. Check for id and accesskey values which are not unique within the document.

  2. Check that attribute values that have an idref value have a corresponding id value.

  3. For tables that use the axis attribute, check that all values listed in the axis attribute have a corresponding id value in a table header cell in the same table.

  4. For client-side image maps, check that the value of the usemap attribute has a corresponding id value if the usemap attribute is not a URL.

Expected Results
  • If step #1, step #3 or step #4 is true or step #2 is false, then this failure condition applies and the content fails the success criterion.


F19: Failure of SC 4.2.1 and 4.2.3 due to not providing a method for the user to find the alternative conforming version of a non-conforming Web unit

Applicability

Sites that provide alternative, WCAG conforming versions of nonconforming primary content.

This technique is referenced from:

Description

This failure technique describes the situation in which an alternate, conforming version of the content is provided, but there is no direct way for a user to tell that it is available or where to find it. Such content fails the success criterion because the user cannot find the conforming version.

Examples

  • A link or a search takes a user directly to one of the nonconforming pages in the Web site. There is neither an indication that an alternate page is available, nor a path to the alternate page from the nonconforming page.

  • Nonconforming pages on the Web site inform the user that a conforming version is available and provide a link to the home page. However, the user must search the site for the conforming version of the page, so the functionality does not meet the requirements of the success criterion.

  • A user is able to use the nonconforming Web site for most pages. But when the user is not able to access a particular page, there is no way to find the conforming version of the page.

Tests

Procedure
  1. Identify a nonconforming page that has an alternative conforming version.

  2. Determine if the nonconforming page provides a link to the conforming version.

Expected Results
  1. If step #2 is false, the content fails the success criterion.


F20: Failure of SC 1.1.1 and 4.1.2 due to not updating text alternatives when changes to non-text content occur

Applicability

Applies to all technologies.

This technique is referenced from:

Description

The objective of this failure condition is to address situations where the non-text content is updated, but the text alternative is not updated at the same time. If the text in the text alternative can not still be used in place of the non-text content without losing information or function, then it fails because it is no longer a text alternative for the non-text content.

Examples

  • Failure Example 1: A Sales chart is updated to October results, but the text alternative still describes September results.

  • Failure Example 2: Pictures on a home page change daily, but text alternatives are not updated at the same time.

  • Failure Example 3: The source attribute of images on a page is updated periodically using script, but the text alternatives are not updated at the same time.

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure
  1. Check each text alternative to see if it is describing content other than the currently-displayed non-text content.

Expected Results
  • If step #1 is true then the text alternative is not up to date with current item, this failure condition applies, and content fails the success criterion.


F22: Failure of SC 3.2.5 due to opening windows that are not requested by the user

Applicability

General

This technique is referenced from:

Description

Failure due to opening new windows when the user does not expect them. New windows take the focus away from what the user is reading or doing. This is fine when the user has interacted with a piece of User Interface and expects to get a new window, such as an options dialog. The failure comes when pop-ups appear unexpectedly.

Examples

Failure Example 1:

When a user navigates to a page, a new window appears over the existing user agent window, and the focus is moved to the new window.

Failure Example 2:

A user clicks on a link, and a new window appears. The original link has no associated text saying that it will open a new window.

Failure Example 3:

A user clicks on the body of a page and a new window appears. No indication that the area that was clicked has functionality is present.

Failure Example 4:

A user clicks on undecorated text within the page and a new window appears. No indication that the text is a link is available.

Resources

No resources available for this technique.

Tests

Procedure
  1. Load the Web unit.

  2. Check if new (additional) windows open.

  3. Find every actionable element, such as links and buttons, in the Web unit.

  4. Activate each element.

  5. Check if activating the element opens a new window.

  6. Check if elements that open new windows have associated text saying that will happen. The text can be displayed in the link, or available through a hidden association such as an HTML title attribute.

Expected Results
  • If step #2 is true, the failure condition applies and the content fails the success criterion

  • If step #5 is true and step #6 is false, the failure condition applies and the content fails the success criterion


F23: Failure of SC 1.4.2 due to playing a sound longer than 3 seconds where there is no mechanism to turn it off

Applicability

Applies to all technologies except those for voice interaction.

This technique is referenced from:

Description

This describes a failure condition for SC involving sound. If sound does not turn off automatically within 3 seconds and there is no way to turn the sound off then SC 1.4.2 would not be met. Sounds that play over 3 seconds when there is no mechanism to turn off the sound included in the content would fall within this failure condition.

Examples

Example 1
  • a site that plays continuous background music

Example 2
  • a site with a narrator that lasts more than 3 seconds before stopping.

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure
  1. Check that there is a way in content to turn off any sound that plays more than three seconds.

Expected Results
  • If step #1 is not true then content fails Success Criterion 1.4.2


F24: Failure of SC 1.4.1 due to specifying foreground colors without specifying background colors or vice versa

Applicability

All technologies that allow user agents to control foreground and background colors through personal stylesheets or other means.

This technique is referenced from:

Description

Users with vision loss or cognitive challenges often require specific foreground and background color combinations. For instance, many people with low vision find it much easier to see a Web page that has white text on a black background, so they may have set their user agent to create this contrast. If the author specifies that the text must be black, then it may override the settings of the user agent and render a page that has black text (specified by the author) on black background (that was set in the user agent). This principle also works in reverse. If the Webmaster forces the background to be white, then the white background specified by the author would be the same color as the white text (which was set in the user agent) rendering the page unusable to the user. Therefore, if the author specifies a foreground text color then they should also specify a background color which has sufficient contrast (link) with the foreground and vice versa.

Examples

Failure Example 1:

In the example below the background color is defined on the body element, however the foreground color is not defined. Therefore, the example fails the Success Criterion.

   
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
  "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
  <html xmlns="<url>http://www.w3.org/1999/xhtml">http://www.w3.org/1999/xhtml</title>">
      <html>
          <head>
              <title>A study of population dynamics</title>
          </head>
          <body bgcolor="white">
              <p> ... document body...</p>
          </body>
  </html>
Failure Example 2:

In the example below the background color is defined on the CSS stylesheet, however the foreground color is not defined. Therefore, the example fails the Success Criterion.

  <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<html>
<head>
 <title>Setting the canvas background</title>
    <style type="text/css">

       body {background-color:white}
    </style>
  </head>
  <body>
    <p>My background is white.</p>
  </body>
</html>
Failure Example 3:

In the example below the foreground color is defined on the body element, however the background color is not defined. Therefore, the example fails the Success Criterion.

 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
   "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<html>
<head>
 <title>A study of population dynamics</title>

</head>
<body color="white">
  <p>... document body...</p>
</body>
</html>
Failure Example 4:

In the example below the foreground color is defined on the CSS stylesheet, however the background color is not defined. Therefore, the example fails the Success Criterion.

 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
   "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<html>
<head>
 <title>Setting the canvas background</title>
    <style type="text/css">
       body {color:white}
    </style>
  </head>

  <body>
    <p>My foreground is white.</p>
  </body>
</html>
Failure Example 5:

In the example below the link text (foreground)color is defined on the body element, however the background color is not defined. Therefore, the example fails the Success Criterion.

  <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" 
    "http://www.w3.org/TR/html4/strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<html>
<head>
 <title>A study of population dynamics</TITLE>
 <style type="text/css">
  a:link { color: red }
  a:visited { color: maroon }
  a:active { color: fuchsia }
 </style>

</head>
<body>
  <p>... document body... <a href="foo.htm">Foo</a></p>
</body>
</html>

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure
  1. Examine the code of the Web unit.

  2. Check to see if a foreground color is specified

  3. Check to see if a background color is specified

Expected Results

If step #2 is true but step #3 is false, OR if step #3 is true but step #2 is false then this failure condition applies and content fails the success criterion.


F25: Failure of SC 2.4.3 due to the title of a Web unit not identifying the contents

Applicability

All technologies.

This technique is referenced from:

Description

This describes a failure condition when the Web unit has a title, but the title does not identify the contents or purpose of the Web unit.

Examples

Failure Example 1

Examples of text that are not titles include:

  • Authoring tool default titles, such as

    • "Enter the title of your HTML document here,"

    • "Untitled Document"

    • "No Title"

    • "Untitled Page"

    • "New Page 1"

  • Filenames that are not descriptive in their own right, such as "report.html" or "spk12.html"

  • Empty text

  • Filler or placeholder text

Failure Example 2

A site generated using templates includes the same title for each page on the site. So the title cannot be used to distinguish among the pages.

Resources

No resources available for this technique.

Tests

Procedure
  1. Check whether the title of each Web unit identifies the contents or purpose of the Web unit .

Expected Results
  • If step #1 is false, then this failure condition applies and the content fails this success criterion.


F26: Failure of SC 1.3.5 due to using a non-text mark alone to convey information

Applicability

All technologies.

This technique is referenced from:

Description

The objective of this technique is to show how using a non-text mark to convey information can make content difficult to comprehend. A non-text mark may be non-text content such as an image, or a font glyph which is not text nor an image of text. Users with cognitive disabilities or those using assistive technologies may have difficulty determining the meaning of the non-text mark. If a non-text mark is used to convey information, provide an alternative using features of the technology or use a different mechanism that can be marked with an alternative to represent the non-text mark. For example, an image with a text alternative can be used instead of the glyph.

Examples

Failure Example 1: Glyphs Used to Indicate Status

An instant messaging application uses two simple glyphs to indicate a person's instant messaging status. A check mark indicates that a person is on-line and available. An "x" character indicates that a person is not available. An assistive technology user could not determine a person's instant messaging status.

Resources

No resources available for this technique.

Tests

Procedure
  1. Examine the page for non-text marks that convey information.

  2. Check whether there are other means to determine the information conveyed by the non-text marks.

Expected Results
  • If step #2 is false, then this failure condition applies and the content fails this success criterion.


F28: Failure of SC 4.1.1 due to using markup that results in inconsistent DOMs in user agents

Applicability

Applies to the Document Object Model (DOM).

This technique is referenced from:

Description

The objective of this technique is to prevent Web pages from being presented inconsistently to users whose assistive technologies utilize a document object model (DOM). Incorrectly nested markup leads to inconsistent DOM representations being generated by user agents. The HTML specification does not define how user agents should deal with incorrectly nested markup, so user agent manufacturers have to define their own methods of dealing with it. In an attempt to honour the author's markup, some user agents introduce extra elements in the DOM to maintain a tree-like structure; other user agents end up with a DOM structure that is no longer a tree. As assistive technology gets more sophisticated and starts to make more use of the DOM, consistency becomes more critical.

Examples

Failure Example 1:

Incorrectly nested tags will cause inconsistencies in the DOM amongst different user agents, such as the following invalid example in HTML 4.01.

<strong><p>ABC</strong>DEF</p>

The above markup results in the following (differing)DOM representations in Firefox 1.5, Internet Explorer 6, and Opera 8.51.

Firefox 1.5

  • DOCTYPE: html

  • HTML

    • HEAD

    • BODY

      • STRONG

      • P

        • STRONG

          • #text: ABC

          #text: DEF

Internet Explorer 6

  • comment: CTYPE html PUBLIC "-//W3C//DTD HTML 4.01//E

  • HTML

    • HEAD

      • TITLE

      BODY

      • STRONG

        • P

          • #text: ABC

          • #text: DEF

        #text: DEF

Opera 8.51

  • HTML

    • BODY

      • STRONG

        • P

          • #text: ABC

          • #text: DEF

Resources

(none currently listed)

Tests

Procedure
  1. Using at least two different user agents examine the DOM generated from the markup. The user agents must have the same capabilities available. For example, if the markup relies on scripting, make certain that both user agents have scripting enabled.

  2. Determine if the DOMs are the same.

Expected Results

If step #2 is false, this failure condition applies and content fails the success criterion.


F30: Failure of SC 1.1.1 due to using text alternatives that are not alternatives (e.g. filenames or placeholder text)

Applicability

Applies to all technologies.

This technique is referenced from:

Description

This describes a failure condition for all techniques involving text alternatives. If the text in the "text alternative" cannot be used in place of the non-text content without losing information or function then it fails because it is not, in fact, an alternative to the non-text content.

Examples

Failure Example 1

Examples of text that are not text alternatives include:

  • placeholder text such as " " or "spacer" or "image" or "picture" etc that are put into the 'text alternative' location on images or pictures.

  • programming references that do not convey the information or function of the non-text content such as "picture 1", "picture 2" or "0001", "0002" or "Intro#1", "Intro#2".

  • filenames that are not valid text alternatives in their own right such as "Oct.jpg" or "Chart.jpg" or "sales\\oct\\top3.jpg"

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure
  1. Check each text alternative to see if it is not actually a text alternative for the non-text content.

Expected Results
  • If step #1 is true then this failure condition applies and content fails the success criterion.


F31: Failure of SC 3.2.4 due to using two different labels for the same function on different pages

Applicability

Applies to all technologies.

This technique is referenced from:

Description

Components that have the same function in different Web units are more easily recognized if they are labeled consistently. If the naming is not consistent, some users may get confused.

Note: Text alternatives that are "consistent" are not always "identical." For instance, you may have an graphical arrow at the bottom of a Web unit that links to the next Web unit. The text alternative may say "Go to page 4." Naturally, it would not be appropriate to repeat this exact text alternative on the next Web unit. It would be more appropriate to say "Go to page 5". Although these text alternatives would not be identical, they would be consistent, and therefore would not be failures for this success criterion.

Examples

Failure Example 1:

One of the most common examples of using inconsistent labels for components with the same function is to use a button that says "search" in one page and to use a button that says "find" on another page when they both serve the identical function.

Failure Example 2:

An online authoring tool that uses a button with "Save page" on one page and "Save" on another page, in both cases for the same function.

Example 3:

A Web site publishes articles online. Each article spans multiple Web pages and each page contains a link to the first page, the next page and the previous page of the article. If the references to the next page read "page 1", "page 2", "page 2" etcetera, the labels are not the same but they are consistent. Therefore, these references are not failures of this success criterion.

Failure Example 4:

An e-commerce application uses a printer icon that allows the user to print receipts and invoices. In one part of the application, the printer icon is labeled "Print receipt" and is used to print receipts, while in another part it is labeled "Print invoice" and is used to print invoices. The labeling is consistent ("Print x"), but the labels are different to reflect the different functions of the icons. Therefore, this example does not fail the success criterion.

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure
  1. In a set of Web units, find components with the same function that are repeated in multiple Web units.

  2. For each component with the same function found in step #1, check that the naming is consistent.

Expected Results

If step #2 is false then this failure condition applies and content fails the success criterion.


F32: Failure of SC 1.3.3 due to using white space characters to control spacing within a word

Applicability

All technologies.

This technique is referenced from:

Description

The objective of this technique is to describe how using blank characters, such as space, tab, line break, or carriage return, to format individual words visually can be a failure to present meaningful sequences properly. Blank characters have no appearance when rendered visually, but affect the positioning of adjacent characters. When blank characters are inserted to control letter spacing within a word, they may change the interpretation of the word or cause it not to be recognized as a single word.

Inserting white space characters into an initialism is not an example of this failure, since the white space does not change the interpretation of the initialism and may make it easier to understand.

The use of white space between words for visual formatting is not a failure, since it does not change the interpretation of the words.

Examples

Failure Example 1: Failure due to adding white space in the middle of a word

This example has white spaces within a word to space out the letters in a heading. Screen readers may read each letter individually instead of the word "Welcome."

<h1>W e l c o m e</h1>

&nbsp; can also be used to add white space, producing similar failures:

<h1>H&nbsp;E&nbsp;L&nbsp;L&nbsp;O</h1>
Failure Example 2: White space in the middle of a word changing its meaning

In Japanese, Han characters(Kanji) may have multiple readings that mean very different things. In this example, the word is read incorrectly because screen readers may not recognize these characters as a word because of the white space between the characters. The characters mean "Tokyo," but screen readers say "Higashi Kyo".

<h1>東 京</h1>
Failure Example 3: Using line break characters to format vertical text

In the row header cell of a data table containing Japanese text, authors often create vertical text by using line break characters. However screen readers are not able to read the word of vertical text correctly because the line breaks occur within the word. In the following example, "東京都"(Tokyo-to) will be read "Higashi Kyo Miyako".

<table>
<caption>表1. 都道府県別一覧表</caption>
<tr>
<td></td>
<th scope="col">(見出しセル 1.)</th>
<th scope="col">(見出しセル 2.)</th>
</tr>
<tr>
<th scope="row">東<br />京<br />都</th>
<td>(データセル 1.)</td>
<td>(データセル 2.)</td>
</tr>
・・・・・・
</table>

Resources

No resources available for this technique.

Tests

Procedure

For each word that appears to have non-standard spacing between characters:

  1. Check whether any words in the text of the content contain white space characters .

Expected Results
  • If step #1 is true, then this failure condition applies and the content fails this success criterion.


F33: Failure of SC 1.3.1 and 1.3.3 due to using white space characters to create multiple columns in plain text content

Applicability

All technologies.

This technique is referenced from:

Description

The objective of this technique is to describe how using white space characters, such as space, tab, or carriage return, to format columns of data in text content is a failure to use structure properly. Assistive technologies will interpret content in the reading order of the current language. Using white space characters to create multiple columns does not provide the information in a natural reading order. Thus, the assistive technology user will not be presented with the information in an understandable manner.

Plain text is not suitable for displaying multiple columns of text. Modify the content to present the data in a different layout. Alternatively, use a technology that provides structural elements to represent columnar data.

Examples

Failure Example 1

The following example incorrectly uses white space characters to format a paragraph into a two column format.

Web Content Accessibility Guidelines      including blindness and low vision, 
2.0 (WCAG 2.0) covers a wide range of     deafness and hearing loss, learning 
issues and recommendations for making     difficulties, cognitive limitations, limited 
Web content more accessible. This         movement, speech difficulties, and 
document contains principles,             others. Following these guidelines will 
guidelines, success criteria, benefits,   also make your Web content more 
and examples that define and explain      accessible to the vast majority of users, 
the requirements for making Web-based     including older users. It will also enable
information and applications accessible.  people to access Web content using 
"Accessible" means usable to a wide       many different devices - including a 
range of people with disabilities,        wide variety of assistive technologies.

If this table was to be interpreted and spoken by a screen reader it would speak the following lines:

  • Web Content Accessibility Guidelines including blindness and low vision,

  • 2.0 (WCAG 2.0) covers a wide range of deafness and hearing loss, learning

  • issues and recommendations for making difficulties, cognitive limitations, limited

  • Web content more accessible. This movement, speech difficulties, and

  • (additional lines eliminated for brevity)

If the text were reflowed, or changed from a fixed to a variable font, or increased in size until lines no longer fit on the page, similar interpretation issues would arise in the visual presentation.

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure
  1. Examine the document for data or information presented in columnar format.

  2. Check whether the columns are created using white space characters to lay out the information.

Expected Results
  • If step #2 is true, then this failure condition applies and the content fails this success criterion.


F34: Failure of SC 1.3.1 and 1.3.3 due to using white space characters to format tables in plain text content

Applicability

All technologies.

This technique is referenced from:

Description

The objective of this technique is to describe how using white space characters, such as space, tab, or carriage return, to format tables in text content is a failure to use structure properly. When tables are created in this manner there is no way to indicate that a cell is intended to be a header cell, no way to associate the table header cells with the table data cells, or to navigate directly to a particular cell in a table.

In addition, assistive technologies will interpret content in the reading order of the current language. Using white space to organize data in a visual table does not provide the information in a natural reading order in the source of the document. Thus, the assistive technology user will not be presented with the information in a logical reading order.

Plain text is not suitable for displaying complex information like tables because the structure of the table cannot be perceived. Rather than using visual formatting to represent tabular relations, present the data in a presentation format other than a table. Alternatively, use a technology that provides structural elements to represent tables.

Examples

Failure Example 1

The following example incorrectly uses white space to format a Menu as a visual table.

Menu
         Breakfast        Lunch           Dinner

Monday   2 fried eggs    tomato soup     garden salad
         bacon           hamburger       Fried Chicken
         toast           onion rings     green beans
                         Oatmeal cookie  mashed potatoes

Tuesday   Pancakes       vegetable soup  Caesar salad
          sausage        hot dogs        Spaghetti with meatballs
          orange juice   potato salad    Italian bread
                         brownie         ice cream

If this table was to be interpreted and spoken by a screen reader it would speak the following lines:

  • Menu

  • Breakfast Lunch Dinner

  • Monday 2 fried eggs tomato soup garden salad

  • bacon hamburger Fried Chicken

  • toast onion rings green beans

  • Oatmeal cookie mashed potatoes

This reading order does not make sense since there is no structure in the table for the assistive technology to identify it as a table. If the text were reflowed, or changed from a fixed to a variable font, or increased in size until lines no longer fit on the page, similar issues would arise in the visual presentation.

Resources

No resources available for this technique.

Tests

Procedure
  1. Examine the document for visually formatted tables.

  2. Check whether the tables are created using white space characters to layout the tabular data.

Expected Results
  • If step #2 is true, then this failure condition applies and the content fails this success criterion.


F36: Failure of SC 3.2.2 due to automatically submitting a form and presenting new content without prior warning when the last field in the form is given a value

Applicability

HTML 4.x and XHTML 1.x.

This technique is referenced from:

Description

Forms are frequently designed so that they submit automatically when the user has filled in all the fields, or when focus leaves the last field. There are two problems with this approach. First is that a disabled user who needs more context may move focus away from the field to the directions on how to fill in the form, or to other text, accidentally submitting the form. The other is that, with some form elements, the value of the field changes as each item is navigated with the keyboard, again accidentally submitting the form. It is better to rely on the standard form behavior of the submit button and enter key.

Examples

Failure Example 1:

This failure example submits a form when the user leaves the last field of a three-field telephone number form. The form will submit if the user leaves the field after editing it, even navigating backwards in the tab order. Developers should not use this method to submit a form, and should instead use a submit button, or rely on the form's default behavior of submitting when the user hits enter in a text field.

 
<form method="get" id="form1">
  <input type="text" name="text1" size="3" maxlength="3"> - 
  <input type="text" name="text2" size="3" maxlength="3"> - 
  <input type="text" name="text3" size="4" maxlength="4" onchange="form1.submit();">
</form> 
Failure Example 2:

This is a deprecated example that submits a form when the user selects an option from the menu. The form will submit as soon as an item from the menu is selected. A user using a keyboard will not be able to navigate past the first item in the menu.

 
<form method="get" id="form2">
 <input type="text" name="text1">
  <select name="select1" onchange="form2.submit();">
    <option>one</option>
    <option>two</option>
    <option>three</option>
    <option>four</option>
  </select>
</form>

Resources

Tests

Procedure
  1. Enter data in all fields on page starting at top.

  2. Enter data in last field and exit from it (tab out of it).

  3. Check whether leaving the last field causes change of context.

Expected Results
  • If step #3 is true, then this failure condition applies and content fails the success criterion.


F37: Failure of SC 3.2.2 due to launching a new window without prior warning when the status of a radio button, check box or select list is changed

Applicability

HTML 4.x and XHTML 1.x.

This technique is referenced from:

User Agent and Assistive Technology Support Notes

Internet Explorer 6 also triggers the onclick event when a radio button with onclick receives focus; adding other event handlers (onxxx attributes) to prevent this does not work.

Description

This document describes a failure that occurs when changing the status of a radio button, a check box or an item in a select list causes a new window to open. It is possible to use scripting to create an input element that causes a change of context (submit the form, open a new page, a new window) when the element is selected. Developers can instead use a submit button (see Providing a submit button to initiate a change of context) or clearly indicate the expected action.

Examples

Failure Example 1:

The example below fails the success criterion because it processes the form when a radio button is selected instead of using a submit button.

  
<script type="text/JavaScript"> 
  function goToMirror(theInput) {
   var mirrorSite = "http://download." + theInput.value + "/"; 
   window.open(mirrorSite); 
  }
</script>
  …
<form name="mirror_form" id="mirror_form" action="" method="get">
       <p>Please select a mirror download site:</p> 
       <p> 
       <input type="radio" onclick="goToMirror(this);" name="mirror" 
       id="mirror_belnet" value="belnet.be" /> 
       <label for="mirror_belnet">belnet (<abbr>BE</abbr>)</label><br /> 
       <input type="radio" onclick="goToMirror(this);" name="mirror" 
       id="mirror_surfnet" value="surfnet.nl" /> 
       <label for="mirror_surfnet">surfnet (<abbr>NL</abbr>)</label><br /> 
       <input type="radio" onclick="goToMirror(this);" name="mirror" 
       id="mirror_puzzle" value="puzzle.ch" /> 
       <label for="mirror_puzzle">puzzle (<abbr>CH</abbr>)</label><br /> 
       <input type="radio" onclick="goToMirror(this);" name="mirror" 
       id="mirror_voxel" value="voxel.com" /> 
       <label for="mirror_voxel">voxel (<abbr>US</abbr>)</label><br /> 
       </p> 
</form>

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure
  1. Find each form in a page.

  2. For each form control that is a radio button, check box or an item in a select list, check if changing the status of the control launches a new window.

  3. For each new window resulting from step 2, check if the user is warned in advance.

Expected Results

If step #3 is false, then this failure condition applies and content fails the success criterion.


F38: Failure of SC 1.1.1 due to omitting the alt-attribute for non-text content used for decorative purposes only in HTML

Applicability

Applies to HTML 4.x and XHTML 1.x.

This technique is referenced from:

Description

This describes a failure condition for text alternatives for images that should be ignored by AT. If there is no alt attribute at all assistive technologies are not able to ignore the non-text content. The alt attribute must be proved and have a null value (i.e. alt="" or alt=" ") to avoid a failure of this success criterion.

Note: Although alt=" " is valid, alt="" is recommended.

Examples

  • Failure Example 1: Decorative images that have no alt attribute

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure
  1. Identify any img and applet elements that are used for purely decorative content;

  2. Check that the alt attribute for these elements exists.

  3. Check that the alt attribute for these elements is null.

Expected Results
  • if step #2 or step #3 is false, this failure condition applies and content fails the success criterion.


F39: Failure of SC 1.1.1 due to providing a text alternative that is not null. (e.g. alt="spacer" or alt="image") for Images that should be ignored by AT

Applicability

Applies to HTML 4.x and XHTML 1.x.

This technique is referenced from:

Description

This describes a failure condition for text alternatives for images that should be ignored by AT. If there is no alt attribute at all assistive technologies are not able to ignore the non-text content. The alt attribute must be proved and have a null value (i.e. alt="" or alt=" ") to avoid a failure of this success criterion.

Note: Although alt=" " is valid, alt="" is recommended.

Examples

  • Failure Example 1: Decorative images that have no alt attribute

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure
  1. Identify any img and applet elements that are used for purely decorative content;

  2. Check that the alt attribute for these elements exists.

  3. Check that the alt attribute for these elements is null.

Expected Results
  • If step #2 or step #3 is false, this failure condition applies and content fails the success criterion.


F40: Failure of SC 2.2.1 due to using meta redirect with a time-out

Applicability

All pages

This technique is referenced from:

Description

meta http-equiv of {time-out}; url=... is often used to automatically redirect users. When this occurs after a time delay, it is an unexpected change of context that may interrupt the user.

It is acceptable to use the meta element to create a redirect when the time-out is set to zero, since the redirect is instant and will not be perceived as a change of context. However, it is preferable to use server-side methods to accomplish this. See Implementing automatic redirects on the server side instead of on the client side.

Examples

Failure Example 1

The page below is a failure because it will redirect to the URL http://www.example.com/newpage after a time-out of 5 seconds.

<html xmlns="http://www.w3.org/1999/xhtml">
   <head>     
      <title>Do not use this!</title>     
      <meta http-equiv="refresh"
      content="5; url=http://www.example.com/newpage" />   
   </head>   
   <body>     
      <p>       
         If your browser supports Refresh, you'll be       
         transported to our        
         <a href="http://www.example.com/newpage">new site</a>        
         in 5 seconds, otherwise, select the link manually.     
      </p>   
   </body> 
</html>

Resources

Tests

Procedure
  1. View a page.

  2. Check that the page does not redirect after a time-out.

Expected Results
  1. #2 is true.


F41: Failure of SC 2.2.1, 2.2.5, and 3.2.5 due to using meta refresh with a time-out

Applicability

HTML 4.x and XHTML 1.x.

This technique is referenced from:

Description

meta http-equiv of refresh is often used to periodically refresh pages or to redirect users to another page. If the time interval is too short, people who are blind will not have enough time to make their screen readers read the page before the page refreshes unexpectedly and causes the screen reader to begin reading at the top. Sighted users may also be disoriented by the unexpected refresh.

Examples

Failure Example 1

This is a deprecated example that changes the user's page at regular intervals. Content developers should not use this technique to simulate "push" technology. Developers cannot predict how much time a user will require to read a page; premature refresh can disorient users. Content developers should avoid periodic refresh and allow users to choose when they want the latest information. (The number in the content attribute is the refresh interval in seconds.)

<html xmlns="http://www.w3.org/1999/xhtml">   
  <head>     
    <title>HTML Techniques for WCAG 2.0</title>     
    <meta http-equiv="refresh" content="60" />   
  </head>   
  <body>
    ...     
  </body> 
</html>
Failure Example 2

This is a deprecated example that redirects the user to another page after a number of seconds. Content developers are recommended to user server-side redirects instead. (The number in the content attribute is the refresh interval in seconds.)

<html xmlns="http://www.w3.org/1999/xhtml">   
  <head>     
    <title>The Tudors</title>     
    <meta http-equiv="refresh" content="10;URL='http://thetudors.example.com/'" />   
  </head>   
  <body>
    <p>This page has moved to a <a href="http://thetudors.example.com/">
    theTudors.example.com</a>. Please note that we now have our own 
    domain name and will redirect you in a few seconds. Please update 
    your links and bookmarks.</p>
  </body> 
</html>

Tests

Procedure
  1. Find meta elements in the document.

  2. For each meta element, check if it contains the attribute http-equiv with value "refresh" (case-insensitive) and the content attribute with a number (representing seconds) greater than 0.

Expected Results
  • If step 2 is true then this failure condition applies and content fails the success criterion.


F42: Failure of SC 1.3.1 due to using scripting events to emulate links

Applicability

HTML 4.01 and XHTML 1.x with Scripting.

This technique is referenced from:

Description

This failure occurs when JavaScript event handlers are attached to elements to ''emulate links''. If scripting events are used to emulate links, user agents including assistive technology may not be able to identify the links in the content as links. They may not be recognized as interactive controls by assistive technology, or they may be recognized as interactive controls but still not recognized as links. Such elements do not appear in the links list generated by user agents or assistive technology.

The <a href> and <area> elements are intended to mark up links.

Attaching event handlers to elements that are not normally interactive, such as span and div, can be quite disorienting to users. Even if care is taken to provide keyboard access to such elements, users may have a difficult time discovering that there are interactive controls in the content or understanding what type of behavior to expect from them. For example, users may not know which keystrokes are supported by the script to activate the element. Additionally, these elements do not generate the same operating system events as interactive elements, so assistive technology may not be notified when the user activates them.

Examples

Failure Example 1: Scripting a <span> element

Scripted event handling is added to a span element so that it functions as a link when clicked with a mouse. Assistive technology does not recognize this element as a link.

<span onclick="this.location.href='newpage.html'">
    Fake link
</span>
Failure Example 2: Scripting an <img> element

Scripted event handling is added to an img element so that it functions as a link when clicked with a mouse. Assistive technology does not recognize this element as a link.

   src="go.gif" 
   alt="go to the new page" 
   onclick="this.location.href='newpage.html'"
Failure Example 3: Scripting an <img> element, with keyboard support

Scripted event handling is added to an img element so that it functions as a link. In this example, the link functionality can be invoked with the mouse or via the Enter key if the user agent includes the element in the tab chain. Nevertheless, the element will not be recognized as a link.

function doNav(url)
{
   window.location.href = url;
}

function doKeyPress(url)
{
   //if the enter key was pressed
   if (window.event.type == "keypress" &&
       window.event.keyCode == 13)
   {
      doNav(url);
   }
}

The markup for the image is:

<p>
	<img src="bargain.jpg"
		tabindex="0" 
		alt="View Bargains"
		onclick="doNav('viewbargains.html');"
		onkeypress="doKeyPress('viewbargains.html');"
	>
</p>
Failure Example 4: Scripting a <div> element

This example uses script to make a div element behave like a link. Although the author has provided complete keyboard access and separated the event handlers from the markup to enable repurposing of the content, the div element will not be recognized as a link by assistive technology.

window.onload = init;

function init()
{
	var objAnchor = document.getElementById('linklike');

	objAnchor.onclick = function(event){return changeLocation(event,
'surveyresults.html');};
	objAnchor.onkeypress = function(event){return changeLocation(event,
'surveyresults.html');};
}

function changeLocation(objEvent, strLocation)
{
	var iKeyCode;

	if (objEvent && objEvent.type == 'keypress')
	{
		if (objEvent.keyCode)
			iKeyCode = objEvent.keyCode;
		else if (objEvent.which)
			iKeyCode = objEvent.which;

		if (iKeyCode != 13 && iKeyCode != 32)
			return true;
	}

	window.location.href = strLocation;
}

The markup for the div element is:

<div id="linklike">
View the results of the survey.
</div>

Resources

No resources available for this technique.

Tests

Procedure
  1. Check whether there are JavaScript event handlers on an element that emulates a link.

  2. Check whether the programmatically determined role of the element is link.

Expected Results
  • If check #1 is true and check #2 is false, then this failure condition applies and content fails the success criterion.


F43: Failure of SC 1.3.1 due to using structural markup in a way that does not represent relationships in the content

Applicability

(X)HTML

This technique is referenced from:

Description

The objective of this technique is to describe a failure that occurs when structural markup is used to achieve a presentational effect, but indicates relationships that do not exist in the content. This is disorienting to users who are depending on those relationships to navigate the content or to understand the relationship of one piece of the content to another. Note that the use of HTML tables for layout is not an example of this failure as long as the layout table does not include improper structural markup such as <th> or <caption> elements.

Examples

Failure Example 1: A heading used only for visual effect

In this example, a heading element is used to display an address in a large, bold font. The address does not identify a new section of the document, however, so it should not be marked as a heading.

<p>Interested in learning more? Write to us at</p> 
<h4>3333 Third Avenue, Suite 300 · New York City</h4>

<p>And we’ll send you the complete informational packet absolutely Free!</p>
Failure Example 2: Using heading elements for presentational effect

In this example, heading markup is used in two different ways: to convey document structure and to create visual effects. The h1 and h2 elements are used appropriately to mark the beginning of the document as a whole and the beginning of the abstract. However, the h3 and h4 elements between the title and the abstract are used only for visual effect — to control the fonts used to display the authors’ names and the date.

<h1>Study on the Use of Heading  Elements in Web Pages</h1>
<h3>Joe Jones and Mary Smith<h3>
<h4>March 14, 2006</h4>
<h2>Abstract</h2>
<p>A study was conducted in early 2006 ...
</p>
Failure Example 3: Using blockquote elements to provide additional indentation

The following example uses blockquote for text that is not a quotation to give it prominence by indenting it when displayed in graphical browsers.

<p>After extensive study of the company Web site, the task force 
identified the following common problem.</p>

<blockquote>
<p>The use of markup for presentational effects made Web 
pages confusing to screen reader users.</p>
</blockquote>

<p>The committee lists particular examples of the problems 
introduced by this practice below.</p>
Failure Example 4: Using the fieldset and legend elements to give a border to text
<fieldset>
<legend>Bargain Corner</legend>
<p>Buy today, and save 20%</p>
</fieldset>

Resources

No resources available for this technique.

Tests

Procedure
  1. Check that each element's semantic meaning is appropriate for the content of the element.

Expected Results
  • If check #1 is false, then this failure condition applies and the content fails the success criterion.


F44: Failure of SC 2.4.6 due to using tabindex to create a tab order that does not follow relationships and sequences in the content

Applicability

(X)HTML

This technique is referenced from:

Description

This document describes a failure that occurs when the tab order does not follow logical relationships and sequences in the content.

Focusable elements like links and form elements have a tabindex attribute. The elements receive focus in ascending order of the value of the tabindex attribute. When the values of the tabindex attribute are assigned in a different order than the relationships and sequences in the content, the tab order no longer follows the relationships and sequences in the content.

One of the most common causes of this failure occurs when editing a page where tabindex has been used. It is easy for the tab order and the content order to fall out of correspondence when the content is edited but the tabindex attributes are not updated to reflect the changes to the content.

Examples

Failure Example 1

The following example incorrectly uses tabindex to specify an alternative tab order:

<ul>
   <li><a href="main.html" tabindex="1">Homepage</a></li>
   <li><a href="chapter1.html" tabindex="4">Chapter 1</a></li>
   <li><a href="chapter2.html" tabindex="3">Chapter 2</a></li>
   <li><a href="chapter3.html" tabindex="2">Chapter 3</a></li>
</ul>

If this list is navigated by the tab key, the list is navigated in the order Homepage, chapter 3, chapter 2, chapter 1, which does not follow the sequence in the content.

Failure Example 2

The tab order has been set explicitly in a Web page by providing tabindex attributes for all fields. Later, the page is modified to add a new field in the middle of the page, but the author forgets to add a tabindex attribute to the new field. As a result, the new field is at the end of the tab order.

Resources

Tests

Procedure
  1. If tabindex is used, check that the tab order specified by the tabindex attributes follows relationships in the content.

Expected Results
  • If check #1 is false, then this failure condition applies and content fails the success criterion.


F46: Failure of SC 1.3.1 due to using th elements, caption elements, or non-empty summary attributes in layout tables

Applicability

(X)HTML

This technique is referenced from:

Description

The objective of this technique is to describe a failure that occurs when a table used only for layout includes either th elements, a summary attribute, or a caption element. This is a failure because it uses structural (or semantic) markup only for presentation. The intent of the HTML table element is to present data.

Assistive technologies use the structure of an HTML table to present data to the user in a logical manner. The th element is used to mark the column and row headers of the table. A screen reader uses the information in th elements to speak the header information that changes as the user navigates the table. The summary attribute on the table element provides a textual description of the table that describes its purpose and function. Assistive technologies make the summary attribute information available to users. The caption element is part of the table and identifies the table.

While the preference is to use CSS for visual formatting, tables are often used to visually layout content in an HTML document. When a table is used for layout purposes the th element should not be used. Since the table is not presenting data there is no need to mark any cells as column or row headers. Likewise, there is no need for an additional description of a table which is only used to layout content. Do not include a summary attribute and do not use the summary attribute to describe the table as, for instance, "layout table". When spoken, this information does not provide value and will only distract users navigating the content via a screen reader. Empty summary attributes are acceptable on layout tables, but not recommended.

Examples

Failure Example 1

Here is a simple example that uses a table to layout content in a three column format. The navigation bar is in the left column, the main content in the middle column, and an additional sidebar is on the right. At the top is a page title. The example marks the page title as <th>, and provides a summary attribute indicating that the table is a layout table.

 <table summary="layout table">
 <tr>
   <th colspan=3>Page Title</th>
 </tr>
 <tr>
   <td><div>navigation content</div></td>
   <td><div>main content</div></td>
   <td><div>right sidebar content</div></td>
 </tr>
 <tr>
   <td colspan=3>footer</td>
 </tr>
 </table>

Resources

No resources available for this technique.

Tests

Procedure
  1. Examine the source code of the HTML document for the table element

  2. If the table is used only to visually lay out elements within the content

    1. Check that the table does not contain any th elements.

    2. Check that the table element does not contain a non-empty summary attribute.

    3. Check that the table element does not contain a caption element.

Expected Results
  • If any check above is false, then this failure condition applies and the content fails the success criterion.


F47: Failure of SC 2.2.2 due to using the blink element

Applicability

HTML and XHTML.

This technique is referenced from:

User Agent and Assistive Technology Support Notes

The blink element is not supported by Internet Explorer. It is supported in Netscape/Mozilla family of user agents and Opera. Not tested in others (e.g., Safari).

Description

The blink element, while not part of the official HTML specification, is supported by many user agents. It causes any text inside the element to blink at a predetermined rate. This cannot be interrupted by the user, nor can it be disabled as a preference. The blinking continues as long as the page is displayed. Therefore, content that uses blink fails the success criterion because blinking can continue for more than three seconds.

Examples

Failure Example 1

A product list page uses the blink element to draw attention to sale prices. This fails the success criterion because users cannot control the blink.

<p>My Great Product <blink>Sale! $44,995!</blink></p>

Tests

Procedure
  1. Examine code for the presence of the blink element.

Expected Results
  • If #1 is true, the content fails the success criterion.


F48: Failure of SC 1.3.1 due to using the pre element to markup tabular information

Applicability

HTML 4.01, XHTML 1.x

This technique is referenced from:

Description

This document describes a failure caused by use of the HTML pre element to markup tabular information. The pre element preserves only visual formatting. If the pre element is used to markup tabular information, the visually implied logical relationships between the table cells and the headers are lost if the user cannot see the screen or if the visual presentation changes significantly.

Instead, the HTML table element is intended to present tabular data. Assistive technologies use the structure of an HTML table to present data to the user in a logical manner. This structure is not available when using the pre element.

Examples

Failure Example 1: A schedule formatted with tabs between columns
 <pre>
 	Monday	Tuesday	Wednesday	Thursday	Friday
 8:00-
 9:00	Meet with Sam				
 9:00-
 10:00			Dr. Williams	Sam again	Leave for San Antonio
 </pre>
Failure Example 2: Election results displayed using preformatted text
 <pre>
   CIRCUIT COURT JUDGE BRANCH 3
                                                  W
                                                   R
                                          M R E     I
                                           A . L     T
                                     M L    R   B     E
                                      I A    Y   E     -
                                       K N        R     I
                                        E G        T     N
                                       -----   -----   -----
0001 TOWN OF ALBION WDS 1-2               22      99       0
0002 TOWN OF BERRY WDS 1-2                52     178       0
0003 TOWN OF BLACK EARTH                  16      49       0
0004 TOWN OF BLOOMING GROVE WDS 1-3       44     125       0
0005 TOWN OF BLUE MOUNDS                  33     117       0
0006 TOWN OF BRISTOL WDS 1-3             139     639       1
0007 TOWN OF BURKE WDS 1-4                80     300       0
0008 TOWN OF CHRISTIANA WDS 1-2           22      50       0

 </pre>

Resources

No resources available for this technique.

Tests

Procedure
  1. Check to see if the pre element is used

  2. For each occurrence of the pre element, check whether the enclosed information is tabular.

Expected Results
  • If check #2 is true, then this failure condition applies and the content fails the success criterion.


F49: Failure of SC 1.3.3 due to changing the meaning of content by positioning information with HTML layout tables

Applicability

HTML, XHTML 1.x

This technique is referenced from:

User Agent and Assistive Technology Support Notes

Early screen readers literally read Web content from the screen, which lead to problems when tables were used for layout where one table cell was meant to be read in its entirety before reading the next table cell. Today's screen readers work with the underlying markup, which means that they do read a table cell in its entirety before moving on to the next cell, but layout tables may still inadvertently introduce problems with the natural reading order of the content.

Description

This failure occurs when a meaningful sequence of content conveyed through presentation is lost because HTML tables used to control the visual placement of the content do not “linearize” correctly. Tables present content in two visual dimensions, horizontal and vertical. However, screen readers present this two-dimensional content in linear order of the content in the source, beginning with the first cell in the first row and ending with the last cell in the last row. The screen reader reads the table from top to bottom, reading the entire contents of each row before moving to the next row. The complete content of each cell in each row is spoken—including the complete content of any table nested within a cell. This is called linearization.

Suppose that a Web page is laid out using a table with 9 columns and 22 rows. The screen reader speaks the content of the cell at Column 1, Row 1 followed by the cells in columns 2, 3, 4 and so on to column 9. However, if any cell contains a nested table, the screen reader will read the entire nested table before it reads the next cell in the original (outer) table. For example, if the cell at column 3, row 6 contains a table with 6 columns and 5 rows, all of those cells will be read before Column 4, Row 6 of the original (outer) table. As a result, the meaningful sequence conveyed through visual presentation may not be perceivable when the content is spoken by a screen reader.

Examples

Failure Example 1: A layout table that does not linearize correctly

An advertisement makes clever use of visual positioning, but changes meaning when linearized.

<table>
<tr>
  <td><img src="logo.gif" alt="XYZ mountaineering"></td>
  <td>top!</td>
</tr>
<tr>
  <td colspan="2">XYZ gets you to the</td>
</tr>
</table>

The reading order from this example would be:

  • XYZ mountaineering top!

  • XYZ gets you to the

Failure Example 2: A layout table that separates a meaningful sequence when linearized

A Web page from a museum exhibition positions a navigation bar containing a long list of links on the left side of the page. To the right of the navigation bar is an image of one of the pictures from the exhibition. To the right of the image is the kind of "placard" text you'd see on the wall next to the object if you were at the museum. Below that text is a heading that says "Description," and below that heading is a description of the image. The image, placard text, Description heading, and text of the description form a meaningful sequence.

A layout table is used to position the elements of the page. The links in the navigation bar are split into different cells in the leftmost column.

<table>
<tr>
	<td><a href="#">Link 1</a></td>
	<td rowspan="20"><img src="img.png" alt="Museum Picture"></td>
	<td rowspan="6"><img src="placard.png" alt="Placard text"></td> 
</tr> 
<tr>
	<td><a href="#">Link 2</a></td>
</tr>
<tr>
	<td><a href="#">Link 3</a></td>
</tr>
<tr>
	<td><a href="#">Link 4</a></td>
</tr>
<tr>
	<td><a href="#">Link 5</a></td>
</tr>
<tr>
	<td><a href="#">Link 6</a></td>
</tr>
<tr>
	<td><a href="#">Link 7</a></td>
	<td rowspan="2"><h2>Image Heading</h2></td> 
</tr> 
<tr>
	<td><a href="#">Link 8</a></td>
</tr>
<tr>
	<td><a href="#">Link 9</a></td>
	<td rowspan="12">Description of the image</td> 
</tr> 
<tr>
	<td><a href="#">Link 10</a></td>
</tr>
 ...
<tr>
	<td><a href="#">Link 20</a></td>
</tr>
</table>

The reading order from this example would be:

  • Link 1

  • Image

  • Placard Text

  • Link 2

  • Link 3

  • Link 4

  • Link 5

  • Link 6

  • Link 7

  • Image Heading

  • Link 8

  • Link 9

  • Link 10

  • ...

  • Link 20

Because the navigation bar links are interleaved with the content describing the image, screen readers cannot present the content in a meaningful sequence corresponding to the sequence presented visually.

Resources

No resources available for this technique.

Tests

Procedure
  1. Linearize the content in either of the following ways:

    • Present the content in source code order

    • Remove the table markup from around the content

  2. Check that the linear reading order matches any meaningful sequence conveyed through presentation.

Expected Results
  • If check #2 is false, then this failure condition applies and the content fails this success criterion.


F50: Failure of SC 2.2.2 due to a script that causes a blink effect without a mechanism to stop the blinking at 3 seconds or less

Applicability

Technologies that support script-controlled blinking of content.

This technique is referenced from:

Description

Scripts can be used to blink content by toggling the content's visibility on and off at regular intervals. It is a failure for the script not to include a mechanism to stop the blinking at 3 seconds or earlier. See Using scripts to control blinking and stop it in three seconds or less for information about how to modify the technique to stop the blinking.

Examples

Failure Example 1

The following example uses script to blink content, but the blink continues indefinitely rather than stopping after three seconds.

...
<script type="text/javascript">
<!--
// blink "on" state
function show()
{
	if (document.getElementById)
	document.getElementById("blink1").style.visibility = "visible";
	settime-out("hide()", 450);
}
// blink "off" state
function hide()
{
	if (document.getElementById)
	document.getElementById("blink1").style.visibility = "hidden";
	settime-out("show()", 450);
}
// kick it off
show();
//-->
</script>
...
<span id="blink1">This content will blink</span>

Tests

Procedure

For each instance of blinking content:

  1. Determine if the blinking stops in 3 seconds or less.

Expected Results

If #1 is false, then the content fails the success criterion.


F52: Failure of SC 3.2.1 due to opening a new window as soon as a new page is loaded without prior warning

Applicability

Applies when scripting is used to open new windows.

This technique is referenced from:

Description

Some Web sites open a new window when a page is loaded, to advertise a product or service. The objective of this technique is to ensure that pages do not disorient users by opening up one or more new windows as soon as a page is loaded. Unless instructions that describe the behavior are provided before the request to open the new page is made, opening a new window as soon as a new page is loaded is a failure condition for this success criterion.

Examples

Note: There are multiple methods by which this failure may be triggered. Two common examples that are supported differently in various versions of user agents are listed as examples below.

Failure Example 1:

The following example is commonly used in HTML 4.01 to open new windows when pages are loaded.

window.onload = showAdvertisement;
 function showAdvertisement()
 {
  window.open('advert.html', '_blank', 'height=200,width=150');
 }
Failure Example 2:

The following example commonly used in XHTML to open new windows when pages are loaded.

if (window.addEventListener) { 
    window.addEventListener("load", showAdvertisement, true);
}
if (window.attachEvent) {
    window.attachEvent("onload", showAdvertisement);
}
function showAdvertisement()
{
window.open('noscript.html', '_blank', 'height=200,width=150');
}

Resources

Tests

Procedure
  1. load a new page

  2. check to see whether a new window has been opened as a result of loading the new page

Expected Results
  • If step 2 is true, then this failure condition applies and content fails the success criterion.


F54: Failure of SC 2.1.1 due to using only pointing-device-specific event handlers (including gesture) for a function

Applicability

Technologies that have event handlers specific to pointing devices.

User Agent and Assistive Technology Support Notes

  • None listed.

This technique is referenced from:

Description

When pointing device-specific event handlers are the only mechanism available to invoke a function of the content, users with no vision (who cannot use devices such as mice that require eye-hand coordination) as well as users who must use alternate keyboards or input devices that act as keyboard emulators will be unable to access the function of the content.

Examples

Failure Example 1

The following example is of an image that responds to a mouse click to go to another page. This is a failure because the keyboard cannot be used to move to the next page. <p><img onmousedown="nextPage();" src="nextarrow.gif" alt="Go to next page"></p>

Resources

Tests

Procedure
  1. Check to see whether pointing-device-specific event handlers are the only means to invoke scripting functions.

Expected Results
  • If any are found, then this failure condition applies and content fails the success criterion.


F55: Failure of SC 2.1.1 due to using script to remove focus when focus is received

Applicability

Applies to all content that supports script.

User Agent and Assistive Technology Support Notes

  • None listed.

This technique is referenced from:

Description

Content that normally receives focus when the content is accessed by keyboard may have this focus removed by scripting. While this is done to remove an undesired visual focus indicator, it removes the keyboard focus completely. This typically means the content can only be accessed by a pointer device, such as a mouse.

Examples

Failure Example 1
<input type="submit" onFocus="this.blur();"> 
Failure Example 2
<a onFocus="this.blur()" href="Page.html"><img src="myImage.gif"></a> 
Failure Example 3
<a href="link.html" onfocus="if(this.blur)this.blur();">Link Phrase</a> 

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure
  1. Use the keyboard to verify that you can get to all interactive elements using the keyboard.

  2. Check that when focus is placed on each element, focus remains there until user moves it.

Expected Results
  • If #2 is false then this failure condition applies and content fails the success criterion.


F57: Failure of SC 4.2.1 and 4.2.3 caused by defaulting to non-conforming version as a result of content negotiation

Applicability

Sites that use content negotiation to serve alternate formats of the same content.

This technique is referenced from:

Description

Content negotiation allows Web servers to offer user agents a choice of several versions of the content. A user agent can specify the content formats it can accept. If the user agent does not support content negotiation or does not support any of the formats available, the server is left with only one option - to deliver a default version. If the default version does not conform to WCAG, users may not be able to access the content and may have no means to obtain the WCAG conforming version.

Examples

  • A Web site contains some content that is implemented in a format that does not support conforming to all WCAG requirements at the targeted level. The site provides conforming versions, however, and uses content negotiation with user agents to determine which version to serve. If the user agent does not support content negotiation or does not indicate that it supports any of the offered formats, the server defaults to the nonconforming version of the content.

Resources

Tests

Procedure

On a Web site that uses content negotiation to serve multiple versions of the same content, one that does not conform to WCAG and others that do conform to WCAG:

  1. Turn off content negotiation in the browser by removing the Accept HTTP header or set the Accept header to "*/*".

  2. Determine if the conforming version of the content is delivered.

Expected Results
  • If #2 is false, the site fails the success criterion.


F58: Failure of SC 2.2.1 due to using server-side techniques to automatically redirect pages after a time-out

Applicability

  • Any server-side scripting language

  • Content does not meet the exceptions in the success criterion for permitted time-outs.

This technique is referenced from:

User Agent and Assistive Technology Support Notes

The Refresh header is not defined in HTTP/1.1 or HTTP/1.0, but it is widely supported by browsers (tested in Firefox 1.0 and IE 6 on Windows).

Description

Server-side scripting languages allow developers to set the non-standard HTTP header "Refresh" with a time-out (in seconds) and a URL to which the browser is redirected after the specified time-out. If the time interval is too short, people who are blind will not have enough time to make their screen readers read the page before the page refreshes unexpectedly and causes the screen reader to begin reading at the top. Sighted users may also be disoriented by the unexpected refresh.

The HTTP header that is set is Refresh: {time in seconds}; url={URI of new location}. It is also possible to omit the URL and obtain a periodically refreshing page, which causes the same problem. The HTTP header that is set is Refresh: {time in seconds}.

Examples

Failure Example 1

The following example is a failure because a timed server-side redirect is implemented in Java Servlets or JavaServer Pages (JSP).

public void doGet (HttpServletRequest request, HttpServletResponse response)
      throws IOException, ServletException {
        response.setContentType("text/html");
	PrintWriter out = response.getWriter();
	response.setHeader("Refresh", "10; URL=TargetPage.html");
	out.println("<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\"
	 \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\">");
	out.println("<html><head><title>Redirect</title></head><body>");
	out.println("<p>This page will redirect you in 10 seconds.</p>");
	out.println("</body></html>");
  }
Failure Example 2

The following example is a failure because a timed server-side redirect is implemented in Active Server Pages (ASP) with VBScript.

 <% @Language = "VBScript" %>
 <% option explicit 
 Response.Clear
 Response.AddHeader "Refresh", "5; URL=TargetPage.htm"
 %><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" 
 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
 <html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">
 …
 <!--HTML code for content that is shown before the redirect is triggered-->
 

Resources

Tests

Procedure
  1. When a Web unit is rendered, check to see if it automatically redirects to another page after some period of time without the user taking any action.

Expected Results
  • If such a redirect is found then this failure condition applies and content fails the success criterion.


F59: Failure of SC 4.1.2 due to using script to make div or span a user interface control in HTML

Applicability

HTML and scripting

User Agent and Assistive Technology Support Notes

This technique is referenced from:

Description

This failure demonstrates how using generic HTML elements to create user interface controls can make the controls inaccessible to assistive technology. Assistive technologies rely on knowledge of the role and current state of a component in order to provide that information to the user. Many HTML elements have well defined roles, such as links, buttons, text fields, etc. Generic elements such as div and span do not have any predefined roles. When these generic elements are used to create user interface controls in HTML the assistive technology may not have the necessary information to describe and interact with the control.

See the resources section below for links to specifications which describe mechanisms to provide the necessary role and state information to create fully accessible user interface controls.

Examples

Example 1

The following example fails because it creates a checkbox using a span and an image.

  <p> 
  <span  onclick="toggleCheckbox('chkbox')"> 
  <img src="unchecked.gif"  id="chkbox" alt=""> Include Signature 
  </span> 
  </p>
Example 2

Here is the scripting code which changes the image source when the span is clicked with the mouse.

 
  var CHECKED = "check.gif"; 
  var UNCHECKED = "unchecked.gif"; 
  function toggleCheckbox(imgId) { 
  var theImg = document.getElementById(imgId); 
  if ( theImg.src.lastIndexOf(CHECKED)!= -1 ) { 
  theImg.src = UNCHECKED; 
  // additional code to implement unchecked action 
  } 
  else { 
  theImg.src = CHECKED; 
  // additional code to implement checked action 
  } 
  } 

A checkbox created in this manner will not work with assistive technology since there is no information that identifies it as a checkbox. In addition, this example is also not operable from the keyboard and would fail guideline 2.1.

Resources

Tests

Procedure
  1. Examine the source code for elements which have event handlers assigned within the markup or via scripting.

  2. If those elements are acting as user interface controls, check that the role of the control is defined.

Expected Results

If check #2 is false and the created user interface control does not have role information, this failure condition applies.


F60: Failure of SC 3.2.5 due to launching a new window when a user enters text into an input field

Applicability

General

This technique is referenced from:

Description

This document describes a failure that occurs when a new window is created in response to a user filling in a text field for other than error reporting.

Examples

Failure Example 1:

This is a deprecated example showing a failure: A user is filling in his mailing address. When he fills in his postal code, a new window opens containing advertisements for services available in his city.

Example 2:

This example is acceptable: A user is filling in his mailing address in a form. When he fills in the postal code field, a script runs to validate that it is a valid postal code. If the value is not valid, a window opens with instructions on how to fill in the field.

Resources

Tests

Procedure
  1. Find all text input form fields

  2. Change the value in each form field

  3. Check if new windows open

  4. For any new windows that open, check if they contain an error message and a button that closes the window returning focus to the initiating form element.

Expected Results
  • If #3 is true and #4 is false then failure condition applies and the content fails this success criterion.


F61: Failure of SC 3.2.5 due to complete change of main content through an automatic update that the user cannot disable from within the content

Applicability

General

This technique is referenced from:

Description

This document describes a failure that occurs when the content filling the user's entire viewport is automatically updated, and the content does not contain options for disabling this behavior.

Examples

Failure Example 1:

A news site automatically refreshes itself to ensure that it has the newest headlines. There is no option to disable this behavior.

Failure Example 2:

A slideshow fills the entire viewport and advances to the next slide automatically. There is no stop button.

Resources

(none currently listed)

Tests

Procedure
  1. open the content

  2. leave the content open for 24 hours

  3. check if the content changed

  4. check if there are settings within the content to disable automatic changes

Expected Results
  1. If both 3 and 4 are true, then this failure condition applies and the content fails this success criterion.


F62: Failure of SC 4.1.1 due to insufficient information in DOM to determine specific relationships in XML

Applicability

Applies to the Document Object Model (DOM) for XML.

This technique is referenced from:

Description

The objective of this technique is to ensure that Web units can be interpreted consistently by user agents, including assistive technology. If specific relationships in a Web unit are ambiguous, different user agents, including assistive technologies, could present different information to their users. Users of assistive technology, for example, may have different information presented to them than users of other mainstream user agents. Some elements and attributes in markup languages are required to have unique values, and if this requirement is not honored, the result can be irregular or not uniquely resolvable content.

Examples

Failure Example 1
  • An id attribute value that is not unique.

  • An SVG document uses id attributes on title elements (for alternative text) in order to reuse in other locations in the document. However, one of the title elements has an id that is also used elsewhere in the document, so the document is ambiguous.

  • A DAISY document uses the imgref attribute on the caption element to link captions with images. However, imgref attribute value does not refer to the id attribute of the img element to which it belongs, so the user agent cannot find the caption for that image.

Resources

(none currently listed)

Tests

Procedure
  1. Check that all id values within the document (as defined by the schema) are unique.

  2. Check that elements or attributes that refer to unique identifiers inside the same document have a corresponding id value.

Note that for XML document types defined by a DTD, this refers to attributes of type ID, IDREF or IDREFS. For XML document types defined by a W3C XML Schema, this refers to elements or attributes of type ID, IDREF or IDREFS. (For compatibility, the types ID, IDREF and IDREFS should only be used on attributes, but using them for elements is possible, according to XML Schema Part 2: Datatypes Second Edition.) For other schema languages, check the corresponding mechanisms for specifying IDs and references to IDs.

Expected Results
  • If #1 or #2 is false, then this failure condition applies and the content fails the success criterion.


2. Client-side Scripting Techniques


SCR1: Allowing the user to extend the default time-out

Applicability

Time-outs that are controlled by client-side scripting.

This technique is referenced from:

Description

The objective of this technique is to allow user to extend the default time-out by providing a mechanism to extend the time when scripts provide functionality that has default time-outs. In order to allow the user to request a longer than default time-out period, the script can provide a form (for example) allowing the user to enter a larger default time-out value. Making this available as a preference setting allows users to indicate their requirements in advance. If warning the user a time-out is about to expire (see Providing a script that warns the user a time-out is about to expire), this form can be made available from the warning dialog.

Examples

  • A Web unit contains current stock market statistics and is set to refresh periodically. When the user is warned prior to refreshing the first time, the user is provided with an option to extend the time period between refreshes.

  • In an online chess game, each player is given a time limit for completing each move. When the player is warned that time is almost up for this move, the user is provided with an option to increase the time.

Resources

Tests

Procedure
  1. On a Web unit that uses scripts to enforce a time limit, wait until the time-out has expired.

  2. Determine if an option was provided to extend the time-out.

Expected Results
  • #2 is true and more time is provided to complete the interaction.


SCR14: Using scripts to make nonessential alerts optional

Applicability

Scripting technologies which use scripting alerts for non-emergency communication.

This technique is referenced from:

User Agent and Assistive Technology Support Notes

This technique was tested successfully with JAWS 6.2

This technique was tested successfully with WindowEyes 5.5

This technique was tested successfully with HomePage Reader 3.04

Description

The objective of this technique is to display a dialog containing a message (alert) to the user. When the alert is displayed, it receives focus and the user must activate the OK button on the dialog to dismiss it. Since these alerts cause focus to change they may distract the user, especially when used for non-emergency information. Alerts for non-emergency purposes such as displaying a quote of the day, helpful usage tip, or count down to a particular event, are not presented unless the user enables them through an option provided in the Web unit.

This technique assigns a global JavaScript variable to store the user preference for displaying alerts. The default value is false. A wrapper function is created to check the value of this variable before displaying an alert. All calls to display an alert are made to this wrapper function rather than calling the alert() function directly. Early in the page, a button is provided for the user to enable the display of alerts on the page. This technique works on a visit by visit basis. Each time the page is loaded, alerts will be disabled and the user must manually enable them. Alternatively, the author could use cookies to store user preferences across sessions.

Examples

Example 1

The script below will display a quote in an alert box every ten seconds, if the user selects the "Turn Alerts On" button. The user can turn the quotes off again by choosing "Turn Alerts Off".

<script type="text/javascript">
var bDoAlerts = false;  // global variable which specifies whether to 
                                       // display alerts or not
/* function to enable/disable alerts.
 * param boolean bOn - true to enable alerts, false to disable them.
*/
function modifyAlerts(isEnabled) {
   bDoAlerts = isEnabled;
}
/* wrapper function for displaying alerts.  Checks the value of bDoAlerts
*and only calls the alert() function when bDoAlerts is true.
*/
function doAlert(aMessage) {
    if (bDoAlerts) {
       alert(aMessage);
    }
}
// example usage - a loop to display famous quotes.
var gCounter = -1;  // global to store counter
// quotes variable would be initialized with famous quotations
var quotes = new Array("quote 1", "quote 2", "quote 3", "quote 4", "quote 5");
function showQuotes() {
   if (++gCounter >= quotes.length) {
     gCounter = 0;
   }
   doAlert(quotes[gCounter]);
   setTimeout("showQuotes();", 10000);
}
showQuotes();
</script>

Within the body of the page, include a way to turn the alerts on and off. Below is one example:

<body>
<p>Press the button below to enable the display of famous quotes 
using an alert box<br />
<button id="enableBtn" type="button" onclick="modifyAlerts(true);">
Turn Alerts On</button><br />
<button id="disableBtn" type="button" onclick="modifyAlerts(false);">
Turn Alerts Off</button></p>

Here is a working example of this code: Demonstration of Alerts.

Tests

Procedure

For a Web unit that supports non-emergency interruptions using a JavaScript alert:

  1. Load the Web unit and verify that no non-emergency alerts are displayed.

  2. Verify there is a mechanism to activate the non-emergency alerts.

  3. Activate the non-emergency alerts and verify that the alerts are displayed.

Expected Results
  • For a Web unit that supports non-emergency interruptions using a JavaScript alert, checks 1, 2, and 3 above are true.


SCR16: Providing a script that warns the user a time-out is about to expire

Applicability

Time-outs exist that are controlled by script.

This technique is referenced from:

Description

The objective of this technique is to notify users that they are almost out of time to complete an interaction. When scripts provide functionality that has time-outs, the script can include functionality to warn the user of imminent time-outs and provide a mechanism to request more time. 20 seconds or more before the time-out occurs, the script provides a confirm dialog that states that a time-out is imminent and asks if the user needs more time. If the user answers "yes" then the time-out is reset. If the user answers "no" or does not respond, the time-out is allowed to expire.

This technique involves time-outs set with the window.setTimeout() method. If, for example, the time-out is set to expire in 60 seconds, you can set the time-out for 40 seconds and provide the confirm dialog. When the confirm dialog appears, a new time-out is set for the remaining 20 seconds. Upon expiry of the "grace period time-out" the action that would have been taken at the expiry of the 60 second time-out in the original design is taken.

Examples

Example 1

A page of stock market quotes uses script to refresh the page every five minutes in order to ensure the latest statistics remain available. 20 seconds before the five minute period expires, a confirm dialog appears asking if the user needs more time before the page refreshes. This allows the user to be aware of the impending refresh and to avoid it if desired.

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"<url>http://www.w3.org/TR/html4/loose.dtd">http://www.w3.org/TR/html4/loose.dtd</title>">
<html lang="en">
<head>
<title>Stock Market Quotes</title>
<script type="text/javascript">
<!--
function timeControl() {
	// set timer for 4 min 40 sec, then ask user to confirm.
	setTimeout('userCheck()', 280000);
}
function userCheck() {
	// set page refresh for 20 sec
	var id=setTimeout('pageReload()', 20000);
	// If user selects "OK" the timer is reset 
	// else the page will refresh from the server.
	if (confirm("This page is set to refresh in 20 seconds. 
	Would you like more time?"))
	{
	clearTimeout(id);
	timeControl();
	}
}
function pageReload() {
	window.location.reload(true);
}
timeControl();
-->
</script>
</head>
<body>
<h1>Stock Market Quotes</h1>
...etc...
</body>
</html>

Tests

Procedure

On a Web unit that has a time-out controlled by a script:

  1. load the page and start a timer that is 20 seconds less than the time-out.

  2. when the timer expires, check that a confirmation dialog is displayed warning of the impending time-out.

Expected Results
  • #2 is true.


SCR18: Providing client-side validation and alert

Applicability

Content that validates user input.

This technique is referenced from:

Description

The objective of this technique is to validate user input as values are entered for each field, by means of client-side scripting. If errors are found, an alert dialog describes the nature of the error in text. Once the user dismisses the alert dialog, it is helpful if the script positions the keyboard focus on the field where the error occurred.

Examples

Example 1

The following script will check that a valid date has been entered in the form control.

<label for="date">Date:</label>
<input type="text" name="date" id="date" 
onchange="if(isNaN(Date.parse(this.value))) 
<pre>alert('This control is not a valid date. 
Please re-enter the value.');" /></pre>

Tests

Procedure

For form fields that require specific input:

  1. enter invalid data

  2. determine if an alert describing the error is provided.

Expected Results
  • #2 is true


SCR19: Using an onchange event on a select element without causing a change of context

Applicability

(X)HTML with support for scripting. This technique uses the try/catch construct of JavaScript 1.4.

User Agent and Assistive Technology Support Notes

This technique has been tested on Windows XP using JAWS 7.0 and WindowEyes 5.5 with both Firefox 1.5 and IE 6. This also works with Home Page Reader 3.04. Note that JavaScript must be enabled in the browser.

This technique is referenced from:

Description

The objective of this technique is to demonstrate how to correctly use an onchange event with a select element to update other elements on the Web unit. This technique will not cause a change of context. When there are one or more select elements on the Web unit, an onchange event on one, can update the options in another select element on the Web unit. All of the data required by the select elements is included within the Web unit.

It is important to note that the select item which is modified is after the trigger select element in the reading order of the Web unit. This ensures that assistive technologies will pick up the change and users will encounter the new data when the modified element receives focus. This technique relies on JavaScript support in the user agent.

Examples

Example 1

This example contains two select elements. When an item is selected in the first select, the choices in the other select are updated appropriately. The first select element contains a list of continents. The second select element will contain a partial list of countries located in the selected continent. There is an onchange event associated with the continent select. When the continent selection changes, the items in the country select are modified using JavaScript via the Document Object Model (DOM). All of the data required, the list of countries and continents, is included within the Web unit.

Overview of the code below

  • countryLists array variable which contains the list of countries for each continent in the trigger select element.

  • countryChange() function which is called by the onchange event of the continent select element.

  • The XHTML code to create the select elements in the body of the Web unit.

<?xml version="1.0" encoding="UTF-8"?> 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
  "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> 
  <head> 
    <meta http-equiv="content-type" content="text/xhtml; charset=utf-8" /> 
    <title>Dynamic Select Statements</title> 
<script type="text/javascript">
 //<![CDATA[ 
 // array of possible countries in the same order as they appear in the country selection list 
 var countryLists = new Array(4) 
 countryLists["empty"] = ["Select a Country"]; 
 countryLists["North America"] = ["Canada", "United States", "Mexico"]; 
 countryLists["South America"] = ["Brazil", "Argentina", "Chile", "Ecuador"]; 
 countryLists["Asia"] = ["Russia", "China", "Japan"]; 
 countryLists["Europe"]= ["Britain", "France", "Spain", "Germany"]; 
 /* CountryChange() is called from the onchange event of a select element. 
 * param selectObj - the select object which fired the on change event. 
 */ 
 function countryChange(selectObj) { 
 // get the index of the selected option 
 var idx = selectObj.selectedIndex; 
 // get the value of the selected option 
 var which = selectObj.options[idx].value; 
 // use the selected option value to retrieve the list of items from the coutnryLists array 
 cList = countryLists[which]; 
 // get the country select element via its known id 
 var cSelect = document.getElementById("country"); 
 // remove the current options from the country select 
 var len=cSelect.options.length; 
 while (cSelect.options.length > 0) { 
 cSelect.remove(0); 
 } 
 var newOption; 
 // create new options 
 for (var i=0; i<cList.length; i++) { 
 newOption = document.createElement("option"); 
 newOption.value = cList[i];  // assumes option string and value are the same 
 newOption.text=cList[i]; 
 // add the new option 
 try { 
 cSelect.add(newOption);  // this will fail in DOM browsers but is needed for IE 
 } 
 catch (e) { 
 cSelect.appendChild(newOption); 
 } 
 } 
 } 
//]]>
</script>
</head>
<body>
  <noscript>This page requires JavaScript be available and enabled to function properly</noscript>
  <h1>Dynamic Select Statements</h1>
  <label for="continent">Select Continent</label>
  <select id="continent" onchange="countryChange(this);">
    <option value="empty">Select a Continent</option>
    <option value="North America">North America</option>
    <option value="South America">South America</option>
    <option value="Asia">Asia</option>
    <option value="Europe">Europe</option>
  </select>
  <br/>
  <label for="country">Select a country</label>
  <select id="country">
    <option value="0">Select a country</option>
  </select>
</body>
 </html>

Here is a working example: Dynamic Select

Resources

(none currently listed)

Tests

Procedure
  1. Navigate to the trigger select element (in this example, the one to select continents) and change the value of the select.

  2. Navigate to the select element that is updated by the trigger (in this example, the one to select countries).

  3. Check that the matching option values are displayed in the other select element.

  4. Navigate to the trigger select element, navigate through the options but do not change the value.

  5. Check that the matching option values are still displayed in the associated element.

It is recommended that the select elements are tested with an assistive technology to verify that the changes to the associated element are recognized.

Expected Results
  • Step #3 and #5 are true.


SCR20: Using both keyboard and other device-specific functions

Applicability

Applies to all content that uses Script to implement functionality.

This technique is referenced from:

Description

The objective of this technique is to illustrate the use of both keyboard-specific and mouse-specific events with code that has a scripting function associated with an event. Using both keyboard-specific and mouse-specific events together ensures that content can be operated by a wide range of devices. For example, a script may perform the same action when a keypress is detected that is performed when a mouse button is clicked. This technique goes beyond the SC requirement for keyboard access by including not only keyboard access but access using other devices as well.

In JavaScript, commonly used event handlers include, onblur, onchange, onclick, ondblclick, onfocus, onkeydown, onkeypress, onkeyup, onload, onmousedown, onmousemove, onmouseout, onmouseover, onmouseup, onreset, onselect, onsubmit, onunload. Some mouse-specific functions have a logical corresponding keyboard-specific function (such as 'onmouseover' and 'onfocus'). The keyboard event handler should be provided, that executes the same function as the mouse event handler.

The following table suggests keyboard event handlers to pair mouse event handlers.

Device Handler Correspondences
Use... ...with
mousedown keydown
mouseup keyup
click [1] keypress [2]
mouseover focus
mouseout blur

1 Although click is in principle a mouse event handler, most HTML user agents process this event when the control is activated, regardless of whether it was activated with the mouse or the keyboard. In practice, therefore, it is not necessary to duplicate this event. It is included here for completeness since non-HTML user agents do have this issue.

2 Since the keypress event handler reacts to any key, the event handler function should check first to ensure the Enter key was pressed before proceeding to handle the event. Otherwise, the event handler will run each time the user presses any key, even the tab key to leave the control, and this is usually not desirable.

Some mouse-specific functions (such as dblclick and mousemove) do not have a corresponding keyboard-specific function. This means that some functions may need to be implemented differently for each device (for example, including a series of buttons to execute, via keyboard, the equivalent mouse-specific functions implemented).

Examples

Example 1

In this example of an image link, the image is changed when the user positions the pointer over the image. To provide keyboard users with a similar experience, the image is also changed when the user tabs to it.

<a href="menu.php" onmouseover="swapImageOn('menu')" onfocus="swapImageOn('menu')" 
onmouseout="swapImageOff('menu')" onblur="swapImageOff('menu')"> 
<img id="menu" src="menu_off.gif" alt="Menu" /> 
</a>
Example 2

This example shows an image for which the keyboard can be used to activate the function. The mouse event onclick is duplicated by an appropriate keyboard event onkeypress. The tabindex attribute ensures that the keyboard will have a tab stop on the image. Note that in this example, the nextPage() function should check that the keyboard key pressed was Enter, otherwise it will respond to all keyboard actions while the image has focus, which is not the desired behavior.

<img onclick="nextPage();" onkeypress="nextPage();" tabindex="0" src="arrow.gif" 
alt="Go to next page"> 

Note: This example uses tabindex on an img element. Even though this is currently invalid, it is provided as a transitional technique to make this function work.

Resources

Tests

Procedure
  1. Find all interactive functionality

  2. Check that all interactive functionality can be accessed using the keyboard alone

Expected Results
  • #2 is true


SCR21: Using functions of the Document Object Model (DOM) to add content to a page

Applicability

ECMAScript used inside HTML 4.x or XHTML 1.x

This technique is referenced from:

User Agent and Assistive Technology Support Notes

This example was successfully tested on Windows XP with IE 6 and Firefox 1.5.0.1 using both JAWS 7 and WindowEyes 5.5. This technique will not work with Home Page Reader. Note that when adding new content onto a page, the screen readers may not automatically speak the new content. In order to insure that new content is spoken, set focus to the new element or make certain that it is added below the current location and will be encountered as the user continues to traverse the page.

Description

The objective of this technique is to demonstrate how to use functions of the Document Object Model (DOM) to add content to a page instead of using document.write or object.innerHTML. The document.write() method does not work with XHTML when served with the correct MIME type (application/xhtml+xml), and the innerHTML property is not part of the DOM specification and thus should be avoided. If the DOM functions are used to add the content, user agents can access the DOM to retrieve the content. The createElement() function can be used to create elements within the DOM. The createTextNode() is used to create text associated with elements. The appendChild(), removeChild(), insertBefore() and replaceChild() functions are used to add and remove elements and nodes. Other DOM functions are used to assign attributes to the created elements.

Note: When adding focusable elements into the document, do not add tabindex attributes to explicitly set the tab order as this can cause problems when adding focusable elements into the middle of a document. Let the default tab order be assigned to the new element by not explicitly setting a tabindex attribute.

Examples

Example 1

This example demonstrates use of client-side scripting to validate a form. If errors are found appropriate error messages are displayed. The example uses the DOM functions to add error notification consisting of a title, a short paragraph explaining that an error has occurred, and a list of errors in an ordered list. The content of the title is written as a link so that it can be used to draw the user's attention to the error using the focus method. Each item in the list is also written as a link that places the focus onto the form field in error when the link is followed.

For simplicity, the example just validates two text fields, but can easily be extended to become a generic form handler. Client-side validation should not be the sole means of validation , and should be backed up with server-side validation. The benefit of client-side validation is that you can provide immediate feedback to the user to save them waiting for the errors to come back from the server, and it helps reduce unnecessary traffic to the server.

Here is the script that adds the event handlers to the form. If scripting is enabled, the validateNumbers() function will be called to perform client-side validation before the form is submitted to the server. If scripting is not enabled, the form will be immediately submitted to the server and validation will occur on the server.

 window.onload = initialise;
 function initialise()
 {
    // Ensure we're working with a relatively standards compliant user agent
    if (!document.getElementById || !document.createElement || !document.createTextNode)
        return;
    // Add an event handler for the number form
    var objForm = document.getElementById('numberform');
    objForm.onsubmit= function(){return validateNumbers(this);};
 }

Here is the validation function. Note the use of the createElement(), createTextNode(), and appendChild() DOM functions to create the error message elements.

function validateNumbers(objForm)
 {
   // Test whether fields are valid
   var bFirst = isNumber(document.getElementById('num1').value);
   var bSecond = isNumber(document.getElementById('num2').value);
   // If not valid, display errors
   if (!bFirst || !bSecond)
   {
      var objExisting = document.getElementById('validationerrors');
      var objNew = document.createElement('div');
      var objTitle = document.createElement('h2');
      var objParagraph = document.createElement('p');
      var objList = document.createElement('ol');
      var objAnchor = document.createElement('a');
      var strID = 'firsterror';
      var strError;
      // The heading element will contain a link so that screen readers
      // can use it to place focus - the desitination for the link is 
      // the first error contained in a list
      objAnchor.appendChild(document.createTextNode('Errors in Submission'));
      objAnchor.setAttribute('href', '#firsterror');
      objTitle.appendChild(objAnchor);
      objParagraph.appendChild(document.createTextNode('Please review the following'));
      objNew.setAttribute('id', 'validationerrors');
      objNew.appendChild(objTitle);
      objNew.appendChild(objParagraph);
      // Add each error found to the list of errors
      if (!bFirst)
      {
         strError = 'Please provide a numeric value for the first number';
         objList.appendChild(addError(strError, '#num1', objForm, strID));
         strID = '';
      }
      if (!bSecond)
      {
         strError = 'Please provide a numeric value for the second number';
         objList.appendChild(addError(strError, '#num2', objForm, strID));
         strID = '';
      }
      // Add the list to the error information
      objNew.appendChild(objList);
      // If there were existing errors, replace them with the new lot,
      // otherwise add the new errors to the start of the form
      if (objExisting)
         objExisting.parentNode.replaceChild(objNew, objExisting);
      else
      {
         var objPosition = objForm.firstChild;
         objForm.insertBefore(objNew, objPosition);
      }
      // Place focus on the anchor in the heading to alert
      // screen readers that the submission is in error
      objAnchor.focus();
      // Do not submit the form
      objForm.submitAllowed = false;
      return false;
   }
 }
 // Function to validate a number
 function isNumber(strValue)
 {
   return (!isNaN(strValue) && strValue.replace(/^\s+|\s+$/, '') !== '');
 } 

Below are the helper functions to create the error message and to set focus to the associated form field.

  // Function to create a list item containing a link describing the error
 // that points to the appropriate form field
 function addError(strError, strFragment, objForm, strID)
 {
   var objAnchor = document.createElement('a');
   var objListItem = document.createElement('li');
   objAnchor.appendChild(document.createTextNode(strError));
   objAnchor.setAttribute('href', strFragment);
   objAnchor.onclick = function(event){return focusFormField(this, event, objForm);};
   objAnchor.onkeypress = function(event){return focusFormField(this, event, objForm);};
   // If strID has a value, this is the first error in the list
   if (strID.length > 0)
      objAnchor.setAttribute('id', strID);
      objListItem.appendChild(objAnchor);
      return objListItem;
   }
 }

 // Function to place focus to the form field in error
 function focusFormField(objAnchor, objEvent, objForm)
 {
   // Allow keyboard navigation over links
   if (objEvent && objEvent.type == 'keypress')
      if (objEvent.keyCode != 13 && objEvent.keyCode != 32)
         return true;
   // set focus to the form control
   var strFormField = objAnchor.href.match(/[^#]\w*$/);
   objForm[strFormField].focus();
   return false;
 }

Here is the HTML for the example form.

<h1>Form Validation</h1>
 <form id="numberform" method="post" action="form.php">
 <fieldset>
 <legend>Numeric Fields</legend>
 <p>
 <label for="num1">Enter first number</label> 
 <input type="text" size="20" name="num1" id="num1">
 </p>
 <p>
 <label for="num2">Enter second number</label> 
 <input type="text" size="20" name="num2" id="num2">
 </p>
 </fieldset>
 <p>
 <input type="submit" name="submit" value="Submit Form">
 </p>
 </form>

Note that the sample form will not submit. This example only demonstrates the creation of error messages when client side validation fails.

Resources

(none currently listed)

Tests

Procedure

For pages that dynamically create new content:

  1. Examine the source code and check that the new content is not created using document.write(), innerHTML, outerHTML, innerText or outerText.

Expected Results
  • Check #1 is true.


SCR22: Using scripts to control blinking and stop it in three seconds or less

Applicability

Technologies that support script-controlled blinking of content.

This technique is referenced from:

Description

The objective of this technique is to control blinking with script so it can be set to stop in less than three seconds by the script. Script is used to start the blinking effect of content, control the toggle between visible and hidden states, and also stop the effect at three seconds or less. The setTimeout() function can be used to toggle blinking content between visible and hidden states, and stop when the number of iterations by the time between them adds up to nearly three seconds.

Examples

Example 1

This example uses Javascript to control blinking of some (X)HTML content. Javascript creates the blinking effect by changing the visibility status of the content. It controls the start of the effect and stops it within three seconds.

...
<div id="blink1" class="highlight">New item!</div>
<script type="text/javascript">
<!--
// blink "on" state
function show()
{
	if (document.getElementById)
	document.getElementById("blink1").style.visibility = "visible";
}
// blink "off" state
function hide()
{
	if (document.getElementById)
	document.getElementById("blink1").style.visibility = "hidden";
}
// toggle "on" and "off" states every 450 ms to achieve a blink effect
// end after 2700 ms (less than three seconds)
for(var i=900; i < 2700; i=i+900)
{
	setTimeout("hide()",i);
	setTimeout("show()",i+450);
}
-->
</script>
...

Tests

Procedure

For each instance of blinking content:

  1. Start a timer for 3 seconds at the start of the blink effect.

  2. When the timer expires, determine if the blinking has stopped.

Expected Results
  • For each instance of blinking content, #2 is true.


SCR24: Using script to open a new window

Applicability

HTML 4.01 and XHTML 1.0

This technique is referenced from:

Description

The objective of this technique is to avoid confusion that may be caused by the appearance of new windows that were not requested by the user. Suddenly opening new windows can disorientate or be missed completely by some users. If the document type does not allow the target attribute (it does not exist in HTML 4.01 Strict or XHTML 1.0 Strict) or if the developer prefers not to use it, new windows can be opened with ECMAScript. The example below demonstrates how to open new windows with script: it adds an event handler to a link (a element) and warns the user that the content will open in a new window.

Examples

Example 1:

Markup:

The script is included in the head of the document, and the link has an id that can be used as a hook by the script.

<script type="text/javascript" src="popup.js"></script>
…
<a href="help.html" id="newwin">Show Help</a

Script:

 
// Use traditional event model whilst support for event registration
// amongst browsers is poor.
window.onload = addHandlers;

function addHandlers()
{
  var objAnchor = document.getElementById('newwin');

  if (objAnchor)
  {
    objAnchor.firstChild.data = objAnchor.firstChild.data + ' (opens in a new window)';
    objAnchor.onclick = function(event){return launchWindow(this, event);}
    // UAAG requires that user agents handle events in a device-independent manner
    // but only some browsers do this, so add keyboard event to be sure
    objAnchor.onkeypress = function(event){return launchWindow(this, event);}
  }
}

function launchWindow(objAnchor, objEvent)
{
  var iKeyCode, bSuccess=false;

  // If the event is from a keyboard, we only want to open the
  // new window if the user requested the link (return or space)
  if (objEvent && objEvent.type == 'keypress')
  {
    if (objEvent.keyCode)
      iKeyCode = objEvent.keyCode;
    else if (objEvent.which)
      iKeyCode = objEvent.which;

    // If not carriage return or space, return true so that the user agent
    // continues to process the action
    if (iKeyCode != 13 && iKeyCode != 32)
      return true;
  }

  bSuccess = window.open(objAnchor.href);

  // If the window did not open, allow the browser to continue the default
  // action of opening in the same window
  if (!bSuccess)
    return true;

  // The window was opened, so stop the browser processing further
  return false;
}

Resources

Tests

Procedure
  1. Activate each link in the document to check if it opens a new window.

  2. For each link that opens a new window, check that it uses script.

Expected Results
  • #2 is true.


3. CSS Techniques


C6: Positioning content based on structural markup

Applicability

All technologies that support CSS

This technique is referenced from:

Description

The objective of this technique is to demonstrate how visual appearance may be enhanced via style sheets while still maintaining a meaningful presentation when style sheets are not applied. Using the positioning properties of CSS2, content may be displayed at any position on the user's viewport. Using structural elements ensures that the meaning of the content can still be determined when styling is not available.

Examples

Example 1

In this example structural markup (definition lists) have been applied to the content. CSS has been used to style the content into columnar form. Each class absolutely positions the content into columns and the margins have been set to 0 to override the default behavior of user agents to display HTML definition lists with the DD element indented.

Here is the content to be displayed:

 <div class="box">
  <dl>
    <dt class="menu1">Products</dt>
    <dd class="item1">Telephones</dd>
    <dd class="item2">Computers</dd>
    <dd class="item3">Portable MP3 Players</dd>
    <dt class="menu2">Locations</dt>
    <dd class="item4">Idaho</dd>
    <dd class="item5">Wisconsin</dd>
    </dt>
  </dl>
 </div>
Example 2

Here is the CSS which positions and styles the above elements:

 .item1 {
   left: 0em;
   margin: 0px;
   position: absolute;
   top: 7em;
 }
 .item2 {
   left: 0em;
   margin: 0px;
   position: absolute;
   top: 8em;
 }
 .item3 {
   left: 0em;
   margin: 0px;
   position: absolute;
   top: 9em;
 }
 .item4 {
   left: 14em;
   margin: 0px;
   position: absolute;
   top: 7em;
 }
 .item5 {
   left: 14em;
   margin: 0px;
   position: absolute;
   top: 8em;
 }
 .menu1 {
   background-color: #FFFFFF;
   color: #FF0000;
   font-family: sans-serif;
   font-size: 120%;
   left: 0em;
   margin: 0px;
   position: absolute;
   top: 3em;
 }
 .menu2 {
   background-color: #FFFFFF;
   color: #FF0000;
   font-family: sans-serif;
   font-size: 120%;
   left: 10em;
   margin: 0px;
   position: absolute;
   top: 3em;
 }
 #box {
   left: 5em;
   position: absolute;
   top: 5em;
 }

Example 3

When style sheets are applied, the data are displayed in two columns of "Products" and "Locations." When the style sheets are not applied, the text appears in a definition list which maintains the structure and reading order.

Resources

Tests

Procedure

For content which uses CSS for positioning

  1. Remove the style information from the document or turn off use of style sheets in the user agent.

  2. Check that the structural relations and the meaning of the content are preserved.

Expected Results
  • Check #2 is true.


C9: Using CSS to include decorative images

Applicability

Any technology that can use CSS to include images.

This technique is referenced from:

Description

The objective of this technique is to provide a mechanism to add purely decorative images and images used for visual formatting to Web content without requiring additional markup within the content. This makes it possible for assistive technologies to ignore the non-text content. Some user agents can ignore or turn off CSS at the user's request, so that background images included with CSS simply "disappear" and do not interfere with display settings such as enlarged fonts or high contrast settings.

Background images can be included with the following CSS properties:

  • background,

  • background-image,

  • content, combined with the :before and :after pseudo-elements,

  • list-style-image.

Note: This technique is not appropriate for any image that conveys information or provides functionality, or for any image primarily intended to create a specific sensory experience.

Examples

Example 1: Background image for an HTML page

The stylesheet for a Web page specifies a background image for the whole page.

 …
<style type="text/css">
body { background: #ffe url('/images/home-bg.jpg') repeat; }
</style>
</head>
<body>
…
Example 2: Background image with CSS for image rollovers

The stylesheet for a Web page uses the CSS background property to create a decorative rollover effects when a user hovers the mouse pointer over a link.

a:hover { background: #ffe url('/images/hover.gif') repeat; color: #000;
   text-decoration: none;
}
Example 3: Background images with CSS to create rounded corners on tabs or other elements

The styleseet for a Web page uses the CSS background property to create rounded corners on elements.

…
<style type="text/css">
 div#theComments { width:600px; }
 div.aComment { background: url('images/middle.gif') repeat-y left top; 
 margin:0 0 30px 0; }
 div.aComment blockquote { background: url('images/top.gif') no-repeat left top; 
 margin:0; padding:8px 16px; }
 div.aComment div.submitter { background:#fff url('images/bottom.gif') no-repeat left top; 
 margin:0; padding-top:30px; }
</style>
</head>
<body>
<div id="theComments">
 <div class="aComment">
  <blockquote>
   <p>Hi John, I really like this technique and I'm gonna use it on my own website!</p>
  </blockquote>
  <div class="submitter">
   <p class="cite"><a href="http://example.com/">anonymous coward</a> from Elbonia</p>
  </div>
 </div>
 <div class="aComment">
 …
 </div>
</div>
…

Resources

Tests

Procedure
  1. Check for the presence of decorative images

  2. Check that they are included with CSS

Expected Results
  • If #1 is true, then #2 is true.


C7: Supplementing link text with hidden text

Applicability

All technologies that support CSS .

This technique is referenced from:

Description

The objective of this technique is to supplement the link text by adding additional text that describes the unique function of the link but styling the additional text so that it is not rendered on the screen by user agents that support CSS. When information in the surrounding context is needed to interpret the displayed link text, this technique provides a complete description of the link unique function while permitting the less complete text to be displayed.

This technique works by creating a CSS selector to target text that is to be hidden. The rule-set for the selector places the text to be hidden in a 1-pixel box with overflow hidden, and positions the text outside of the viewport. This ensures the text does not display on screen but remains accessible to assistive technologies such as screen readers and braille displays. Note that the technique does not use visibility:hidden or display:none properties, since these can have the unintentional effect of hiding the text from assistive technology in addition to preventing on-screen display.

Examples

The following examples use the CSS selector and rule-set below:

a span { height: 1px; width: 1px; position: absolute; overflow: hidden; top: -10px; }
Example 1

This example describes a news site that has a series of short synopsis of stories followed by a link that says "full story". Hidden link text describes the purpose of the link.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" 
  "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> 
<head>
<meta http-equiv="Content-Type" content="text/xhtml; charset=UTF-8" /> 
<link href="access.css" rel="stylesheet" type="text/css" />
<title>Hidden Link Text</title>
</head>
<body> 
<p>Washington has announced plans to stimulate economic growth.
  <a href="#"> <span>Washington stimulates economic growth </span>
  Full Story</a></p>
</body>
</html>
Example 2

This example describes a resource that has electronic books in different formats. The title of each book is followed by links that say "HTML" and "PDF." Hidden text describes the purpose of each link.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" 
 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> 
<head>
<meta http-equiv="Content-Type" content="text/xhtml; charset=UTF-8" /> 
<link href="access.css" rel="stylesheet" type="text/css" />
<title>Hidden Link Text </title>
</head>
<body>
<dl>
<dt>Winnie the Pooh </dt>
   <dd><a href="winnie_the_pooh.html">
      <span>Winnie the Pooh </span>HTML</a></dd>
   <dd><a href="winnie_the_pooh.pdf">
         <span>Winnie the Pooh </span>PDF</a></dd>
<dt>War and Peace</dt>
    <dd><a href="war_and_peace.html">
      <span>War and Peace </span>HTML</a></dd> 
    <dd><a href="war_and_peace.pdf">
      <span>War and Peace </span>PDF</a></dd>
</dl>
</body>
</html>

Resources

No resources available for this technique.

Tests

Procedure

For each anchor element using this technique:

  1. Check that an element has been defined that confines its display to a pixel and positions text outside the display with overflow hidden

  2. Check that the element of that class is included in the content of the anchor

  3. Check that the combined content of the anchor describes the purpose of the link

Expected Results
  • All checks above are true.


C8: Using CSS letter-spacing to control spacing within a word

Applicability

All technologies that support CSS.

This technique is referenced from:

Description

The objective of this technique is to demonstrate how the visual appearance of spacing in text may be enhanced via style sheets while still maintaining meaningful text sequencing. The CSS letter-spacing property helps developers control the amount of white space between characters. This is recommended over adding blank characters to control the spacing, since the blank characters can change the meaning and pronunciation of the word.

Examples

Example 1: Separating characters in a word

The following CSS would add the equivalent of a space between each character in a level-2 heading:

h2
{
	letter-spacing: 1em;
}

So for the markup:

<h2>Museum</h2>

the rendered result might look something like:

M u s e u m

Resources

Tests

Procedure

For each word that appears to have non-standard spacing between characters:

  1. Check whether the CSS letter-spacing property was used to control spacing.

Expected Results
  • Check #1 is true.


4. General Techniques


G1: Adding a link at the top of each page that goes directly to the main content area

Applicability

All technology that contains links

This technique is referenced from:

Description

The objective of this technique is to provide a mechanism to bypass blocks of material that are repeated on multiple Web units. The first interactive item in the Web unit is a link to the beginning of the main content. Activating the link sets focus beyond the other content to the main content.

Examples

Example 1: An online newspaper

An on-line newspaper contains many sections of information: a search function, a corporate banner, sidebars, minor stories, how to contact the newspaper, etc. The lead story is located in the middle of the page. The first link that the user reaches when tabbing through the page is titled "Skip to Lead Story". Activating the link moves visual focus to the story. Pressing tab again takes the user to the first link in the main story.

Example 2: A "Skip to main content" link

A Web page includes a variety of navigation techniques on each page: a bread crumb trail, a search tool, a site map, and a list of related resources. The first link on the page is titled "Skip to Main Content". A user activates the link to skip over the navigation tools.

Resources

(none currently listed)

Tests

Procedure
  1. Check that a link is the first focusable control on the Web unit.

  2. Check that the description of the link communicates that it links to the main content.

  3. Check that activating the link moves the focus to the main content.

  4. Check that after activating the link, the keyboard focus has moved to the main content

Expected Results
  • All checks above are true.


G4: Allowing the content to be paused and restarted from where it was stopped

Applicability

Any technology that includes moving or scrolling content.

This technique is referenced from:

Description

The objective of this technique is to provide a way to pause movement or scrolling of content. If the user needs to pause the movement, to reduce distraction or to have time to read it, they can do so, and then restart it as needed. This mechanism can be provided either through interactive controls that conform to WCAG or through keyboard shortcuts. If keyboard shortcuts are used, they are documented.

Examples

  • A site contains a scrolling news banner at the top of the page. Users who need more time to read it can press the Escape key to pause the scrolling. Pressing Escape again restarts it.

  • A Web page contains a link labeled "How to tie a shoe" which links to a Flash animation. Text immediately preceding the link informs the user that pressing the spacebar will pause the animation and restart it again.

Tests

Procedure

On a page with moving or scrolling content,

  1. Use the mechanism provided in the Web unit or by the user agent to pause the moving or scrolling content.

  2. Check that the moving or scrolling has stopped and does not restart by itself.

  3. Use the mechanism provided to restart the moving content.

  4. Check that the movement or scrolling has resumed from the point where it was stopped.

Expected Results
  • #2 and #4 are true.


G5: Allowing users to complete an activity without any time limit

Applicability

This technique applies to any technologies or methods supporting the implementation of an activity which does not require timed interaction for its functionality.

This technique is referenced from:

Description

The objective of this technique is to provide users with all the time they need to complete an activity. This technique involves providing a specified activity which does not require timed interaction. Users are allowed as much time as they need to interact with the activity.

Examples

  • An interactive exam for a course provides all questions on one Web unit. Users can take as much time as they need to complete it.

  • In an interactive game, users can take as much time as they like on their turn instead of having to complete their move within a limited amount of time.

  • In an online auction, each bidder can submit only one bid rather than submitting multiple competitive bids based on timing. The bidding is open for a full day, providing enough time for anyone to complete the simple bid form. Once bidding is closed, the best bid wins.

Resources

Tests

Procedure
  1. Determine if any timed interactions are present.

Expected Results
  • #1 is false.


G7: Associating a title with a Web page

Applicability

All technologies

This technique is referenced from:

Description

The objective of this technique is to ensure that all Web pages have titles associated with them that define in a simple phrase the purpose of the Web page. This helps users to orient themselves quickly within a set of Web pages without having to search for orientation information in the content of the Web pages themselves.

Examples

Example 1: Web Content

The title of Web Content Accessibility Guidelines 2.0 is "Web Content Accessibility Guidelines 2.0".

  • The introduction has the title "Introduction

  • The main body has the title "WCAG 2.0 Guidelines"

  • Appendix A has the title "Glossary"

  • Appendix B has the title "WCAG 2.0 Checklist"

  • Appendix C has the title "Acknowledgements"

  • Appendix D has the title "The differences between WCAG 1.0 and WCAG 2.0"

  • Appendix E has the title "References"

Example 2: An audio file

A podcast is associated with the title "Today's Tech Tips" by setting the id3 property of the .mp3 file.

Example 3: A video clip

A video clip is associated with a title using the meta element in SMIL 1.0 or SMIL 2.0, plus the title attribute of the main par element in the SMIL file.

Example 4: An image

A .JPEG image is associated with a title using EXIF metadata stored in the image file.

Note: Current user agents do not read this metadata.

Resources

No resources available for this technique.

Tests

Procedure
  1. Examine each Web page in the set

  2. Check whether each Web page is associated with a title

Expected Results
  • #2 is true.


G8: Creating an extended audio description for the multimedia content

Applicability

Any audio multimedia technology

This technique is referenced from:

Description

The objective of this technique is to all additional audio description to be inserted into a multimedia presentation when there is not enough time in the gaps int the dialog. This is done by simply freezing the image so that additional audio description of the video can be played. When the description is finished, the multimedia continues.

This technique provides people who are blind or who otherwise would miss information presented visually with additional audio description beyond that which can be provided by standard audio descriptions. Often the gaps in dialog are insufficient to allow enough audio description to be inserted to cover all the important visual information being presented. This technique freezes the multimedia presentation to allow additional audio description to be played. The multimedia presentation is then resumed.

Because it disrupts viewing for those who do not need the additional description, techniques that allow you to turn the feature on and off are often provided. Alternately, versions with and without the additional description can be provided.

Examples

Example 1

Example 1: A Training film has narrative that runs almost continuously throughout. An alternative version is available for people who have difficulty viewing the video portion. The alternative version freezes the video and provides audio description of key information.

Resources

Tests

Procedure
  1. Play multimedia with extended audio description enabled

  2. Check to see if multimedia freezes from time to time to allow audio description to convey important information regarding visual content

Expected Results
  • #2 is true


G9: Creating captions for live multimedia

Applicability

Applies to all technologies that present Audio Visual information

This technique is referenced from:

Description

The objective of this technique is to allow users who cannot hear to be able to access real-time multimedia broadcasts. It is more difficult to create accurate real-time captions because there is little time to correct mistakes or to listen a second time or consult someone to be sure the words are accurately reproduced. It is also harder to simplify or paraphrase information if it is flowing too quickly.

Real-time typing text entry techniques exist using stenographic and rapid typing technologies. Re-voicing speech-to-text (where a person listens to speech and then carefully re-voices it into a computer trained to their speech) is used today for telephone relay services and may be used in the future for captioning. Eventually speech-to-text with correction will be possible.

Examples

Example 1

Example 1: A television studio uses a real-time captioning service to create captions for its evening news online.

Resources

(none)

Tests

Procedure
  1. a procedure and policy are in place to ensure that captions are delivered in real-time

Expected Results
  • #1 is true


G10: Creating components using a technology that supports the accessibility API features of the platforms on which the user agents will be run to expose the names and roles, allow user-settable properties to be directly set, and provide notification of changes

Applicability

programming technologies that have standard components that are programmed to interface with accessibility APIs

This technique is referenced from:

Description

The objective of this technique is to allow assistive technology to understand Web content so that it can convey equivalent information to the user through an alternate user interface.

Sometimes content is not created using markup language but rather using a programming language or tools. In many cases, these technologies have interface components that are already programmed to interface with accessibility APIs. If and author uses these components and fills in the properties (e.g. name, etc) the resulting user interface components in the content will be accessible to assistive technology.

However, if an author wants to create a user interface component that is new and they cannot use standard components, then they need to be sure to add the accessibility provisions themselves - and implement them in a way that is compatible with the accessibility API.

Examples

Example 1

Example 1: A Web unit uses java to create an applet. A group of authors wants to create an entirely new type of interface component so they can not use existing Java objects. They use Java swing classes to create their component because the Java swing classes already have provisions for connecting to different accessibility APIs. Using the Java swing classes they are able to create an interface component that exposes its name and role, is able to be set by AT and alerts AT to any updates.

Example 2: A Web unit uses an original ActiveX control that is written in the C++ programming language. The control is written to expliticly support the Microsoft Active Accessibility (MSAA) API to expose information about accept commands. The control then interacts directly with assistive technology running the user agent on systems that support MSAA.

Resources

(none currently listed)

Tests

Procedure
  1. Render content using an accessible User Agent

  2. Use an Accessibility Tool designed for the Accessibility API of the User agent to evaluate each user interface component

  3. Check that name and role for each user interface component is found by the tool.

  4. Change the values on the component

  5. Check that the Accessibility tool is alerted.

Expected Results
  • Step #3 and #5 are true for each user interface component


G11: Creating content that blinks for less than 3 seconds

Applicability

Technologies that support blinking content.

This technique is referenced from:

Description

The objective of this technique is to minimize the distraction caused by blinking content and enable users to re-focus on the other content on the page.

Blinking content can be created using a variety of technologies, many of which include options to loop blinking content continuously or to otherwise specify the amount of time the blinking content is displayed. Limiting the blinking of content to three seconds minimizes the distraction that blinking can cause. This will benefit people with certain types of learning disabilities and people with low vision.

Examples

  • An animated image is used to highlight items on sale. Within a list of items for purchase, an image of a red tag followed by the phrase "On sale" is used to indicate items being offered at a reduced price. The image of the red tag blinks on loading of the page and stops within three seconds.

Tests

Procedure
  1. Find all items that blink.

  2. For each item that blinks, determine if the interval between the start and end of the blinking is less than three seconds.

Expected Results
  • #2 is true.


G13: Describing what will happen before a change to a form control is made

Applicability

Applies to content that includes forms.

User Agent and Assistive Technology Support Notes

(none listed)

This technique is referenced from:

Description

The objective of this technique is to provide information to users about what will happen when a change to a form control results in a change of context. Because changing the value of a form control does not typically result in a change of context, it is important that authors provide instructions that make the user aware of the behavior in advance. Where possible, it is a good idea to programmatically associate the instructions describing the change with the form control itself.

Examples

Example 1
  1. A series of radio buttons at the top of a page include options for German, French and Spanish. Instructions precede the buttons that instruct the user that the language will be changed upon selecting an option.

  2. A 50 question online survey displays one question at a time. Instructions appear at the beginning of the survey that explain that users will be taken to the next question of the survey upon selecting an answer to each question.

Resources

(none currently listed)

Tests

Procedure
  • locate content where changing the setting of a form control results in a change of context

  • check to see that an explanation of what will happen when the control is changed is available prior to the controls activation

Expected Results
  • #2 is true.


G14: Ensuring that color encoded information is also available in text

Applicability

All technologies that support color.

This technique is referenced from:

Description

The objective of this technique is to ensure that when color is used to convey information, such as required form fields, the information conveyed by the color is also conveyed explicitly in text.

Examples

Example 1: A color-coded schedule

The schedule for sessions at a technology conference is organized into three tracks. Sessions for Track 1 are displayed over a blue background. Sessions in Track 2 are displayed over a yellow background. Sessions in Track 3 are displayed on a green background. After the name of each session is a code identifying the track in text: T1 for Track 1, T2 for Track 2, and T3 for Track 3.

Example 2: A color-coded schedule with icons

The schedule for sessions at a technology conference is organized into three tracks. Next to the title of each session is a colored icon showing what track it belongs to: blue icons represent track 1, yellow icons represent Track 2, and green icons represent Track 3. Each icon is associated with a text alternative reading "Track 1," "Track 2," or "Track 3," as appropriate.

Example 3: A table showing the conference schedule

The schedule for sessions at a technology conference is organized into three tracks. The schedule for each day is shown in a data table with headers for Time, Title, and Track . Sessions for Track 1 are displayed over a blue background. Sessions in Track 2 are displayed over a yellow background. Sessions in Track 3 are displayed on a green background

Example 4: A form with required fields

A form contains several required fields. The labels for the required fields are displayed in red. In addition, at the end of each label is an asterisk character, *. The instructions for completing the form indicate that "all required fields are displayed in red and marked with an asterisk *", followed by an example.

Example 5: A form with a green submit button

An on-line loan application explains that green buttons advance in the process and red buttons cancel the process. A form contains a green button containing the text Go. The instructions say "Press the button labeled Go to submit your results and proceed to the next step."

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure

For each item where color is used to convey information:

  1. Check that the information conveyed is also available in text and that the text is not conditional content.

Expected Results
  • Check #1 is true.


G15: Ensuring that content does not violate the general flash threshold or red flash threshold

Applicability

Applies to any technology

This technique is referenced from:

Description

The purpose of this technique is to allow people who have photosensitive seizures to view Web sites without encountering material that is likely to cause a seizure. Warnings can be provided but people may miss them and children may not be able to read or understand them. With this technique all material is checked and if it violates flash or red flash thresholds it is either not put on the site or it is modified so that it does not violate the thresholds.

Examples

  • An animation of a thunderstorm shows six flashes of lightning. The flashes are so fast that the general flash threshold is violated. The animation is modified to create a short pause after each pair of lightning flashes. After the changes are made, the animation does not violate the general flash threshold.

Resources

(none currently listed)

Tests

Procedure
  1. Check to see if content violates the flash and/or red flash thresholds by either

    • visually checking that there are no more than 2 flashes of any kind in a row OR

    • using a tool that will check for General Flash or Red Flash thresholds automatically

Expected Results
  • Step 1 is false


G17: Ensuring that luminosity contrast of at least 10:1 exists between text and background behind the text

Applicability

Any technology that produces visual output.

This technique is referenced from:

Description

The objective of this technique is to make sure that users can read text that is presented over a background. This technique goes beyond the 5:1 contrast technique to provide a higher level of contrast to make it easier for people with low vision to read.

If the background is a solid color (or all black or all white) then the luminosity contrast of the text can be maintained by making sure that each of the text letters have 10:1 luminosity contrast with the background.

If the background or the letters vary in luminosity (or are patterned) then the background around the letters can be chosen or shaded so that the letters maintain 10:1 luminosity contrast with the background behind them even if they do not have that luminosity contrast with the entire background.

The luminosity contrast can sometimes be maintained by changing the luminosity of the letters as the luminosity of the background changes across the page.

Another method is to provide a halo around the text that provides the necessary luminosity contrast if the background image or color would not normally be sufficiently different in luminosity.

Examples

Example 1

Example 1: A black background is chosen so that light colored letters that match the company’s logo can be use.

Example 2

Example 2: Text is placed over a picture of the college campus. Since a wide variety of colors and darknesses appear in the picture the area behind the text is fogged white so that the picture is very faint and the maximum darkness is still light enough to maintain a 10:1 luminosity with the black text written over the picture.

Resources

(none currently listed)

Tests

Procedure
  1. Measure the luminosity of each letter (unless they are all uniform) using the formula:

    • Luminosity = 0.2126 * ((R / FS) ^ 2.2) + 0.7152 * ((G / FS) ^ 2.2) + 0.0722 * ((B / FS) ^ 2.2)

    • where R, G, and B are the Red, Green, and Blue RGB values of the color, and FS is the maximum possible full scale RGB value for R, G, and B (255 for eight bit color channels).

    • For aliased letters use luminosity two pixels in from the edge of the letter.

    Measure the luminosity of the background pixels immediately next to the letter using same formula.

  2. Calculate the luminosity contrast ratio using the following formula.

    • Luminosity Contrast Ratio = (L1+.05) / (L2+.05).

    • where L1 is the higher value (of text or background) and L2 is the lower value.

    Check that the luminosity contrast ratio is equal to or greater than 10:1

Expected Results
  • #4 is true


G18: Ensuring that luminosity contrast of at least 5:1 exists between text and background behind the text

Applicability

Any technology that produces visual output.

This technique is referenced from:

Description

The objective of this technique is to make sure that users can read text that is presented over a background. This technique uses a lower threshold for contrast to allow more flexibility by authors in color choices.

If the background is a solid color (or all black or all white) then the luminosity contrast of the text can be maintained by making sure that each of the text letters have 5:1 luminosity contrast with the background.

If the background or the letters vary in luminosity (or are patterned) then the background around the letters can be chosen or shaded so that the letters maintain 5:1 luminosity contrast with the background behind them even if they do not have that luminosity contrast with the entire background.

The luminosity contrast can sometimes be maintained by changing the luminosity of the letters as the luminosity of the background changes across the page.

Another method is to provide a halo around the text that provides the necessary luminosity contrast if the background image or color would not normally be sufficiently different in luminosity.

Examples

Example 1

Example 1: A black background is chosen so that light colored letters that match the companies logo can be use.

Example 2

Example 2: Text is placed over a picture of the college campus. Since a wide variety of colors and darknesses appear in the picture the area behind the text is fogged white so that the picture is very faint and the maximum darkness is still light enough to maintain a 5:1 luminosity with the black text written over the picture.

See also the contrast samples at the bottom of the page.

Resources

(none currently listed)

Tests

Procedure
  1. Measure the luminosity of each letter (unless they are all uniform) using the formula:

    • Luminosity = 0.2126 * ((R / FS) ^ 2.2) + 0.7152 * ((G / FS) ^ 2.2) + 0.0722 * ((B / FS) ^ 2.2)

    • where R, G, and B are the Red, Green, and Blue RGB values of the color, and FS is the maximum possible full scale RGB value for R, G, and B (255 for eight bit color channels).

    • For aliased letters use luminosity two pixels in from the edge of the letter.

    Measure the luminosity of the background pixels immediately next to the letter using same formula.

  2. Calculate the luminosity contrast ratio using the following formula.

    • Luminosity Contrast Ratio = (L1+.05) / (L2+.05).

    • where L1 is the higher value (of text or background) and L2 is the lower value.

    Check that the luminosity contrast ratio is equal to or greater than 5:1

Expected Results

The luminosity contrast ratio is equal to or greater than 5:1

  • #4 is true


G19: Ensuring that no component of the content flashes more than three times in any 1-second period

Applicability

Applies to any technology

This technique is referenced from:

Description

The objective of this technique is to avoid flashing at rates that are known to cause seizures if the flashes are bright and large enough. Since some users may be using screen enlargers, this technique limits the flashing of any size content to no more than three flashes in any 1-second period.

Note 1: This technique is stricter than the Level 1 success criterion but is easier to test and can be used to meet the Level 1 success criterion because all failure thresholds in the Level 1 success criterion involve flashing 3.5 flashes or more within one second. Most content does not flash at all and even content that blinks does not blink this fast except on rare occasions. Therefore, in order to avoid having to carry out the more complex testing specified by the success criterion, one could follow this technique to ensure that content only flashes one, two, or at most three times in any 1-second period.

Note 2: Regarding 3.5 Flashes; if there are seven transitions from dark to light or light to dark, it would be 3.5 flashes, which is more than the allowed 3 flashes (6 transitions).

Examples of 3.5 flashes or 7 transitions:

  • STARTING DARK-LIGHT-DARK-LIGHT-DARK-LIGHT-DARK-LIGHT or

  • STARTING LIGHT-DARK-LIGHT-DARK-LIGHT-DARK-LIGHT-DARK.

Examples

  • Content has lightning flashes. Content is designed so that lightning only flashes two or three times without a pause in flashing.

Resources

Tests

Procedure
  1. Check that there are no more than three flashes during any 1-second period.

  2. If there are three flashes, check that the Light/Dark status at the end of the 1 second period is the same as at the start.

Expected Results
  • Both Step one and Step 2 are true.


G20: Ensuring that the only way to get to an inaccessible version is from a link from the accessible version

Applicability

Content where a nonconforming and conforming version are provided as alternatives to each other.

This technique is referenced from:

Description

The objective of this technique is to ensure that users can always access an accessible version of the content. When content is provided in a format that does not conform to WCAG, the site as a whole can still conform if alternate versions of the inaccessible content are provided. The success criterion requires that alternate versions are available "from the same URI" as the nonconforming version. It is the intent of that wording that it can be sufficient to provide a link to conforming content from the nonconforming content (see Providing a link at the top of the nonconforming content that points to an alternate version that does meet WCAG 2.0 Level 1 success criteria (future link)).

In order for the link to alternate content to fulfill its intent, the link needs to conform to WCAG requirements, that is, be accessible. In some technologies, even though the content as a whole may not conform, a link can be provided that does conform. In other technologies, however, it is not even possible to provide a link to alternate content within that technology that conforms. Users may be unable to find the alternate content if the only pointer is in an inaccessible technology.

This technique describes how to provide alternate content in such a situation. In this technique, the WCAG conforming version contains a link to the nonconforming version. This way users access the conforming content, and only access the nonconforming content if they wish, via a link. In order to ensure users do not accidentally get "stuck" in inaccessible content, the nonconforming version is excluded from search engine results, site maps (unless the conforming version is also included), etc.

Examples

  • An online physics course uses a proprietary modeling language to provide interactive demonstrations of physical processes. Because the technology is new and not widely used, it does not provide accessibility features supported by user agents. Students in the course access a WCAG conforming description of the processes and models, but that is not interactive. A link is provided to the nonconforming enhanced interactive version. Students may choose to access the interactive version, but those who do not are still able to learn about the process.

Tests

Procedure

Where WCAG conforming alternatives are provided for nonconforming content:

  1. Check that there is a link to the nonconforming content from the conforming content.

  2. Check that the nonconforming content does not appear in search engine results, site maps, and the site's regular navigation.

Expected Results
  • #1 and #2 are true.


G21: Ensuring that users are not trapped in content

Applicability

All technologies which support interactive operation.

This technique is referenced from:

Description

The objective of this technique is to ensure that keyboard users do not become trapped in a subset of the content that can only be exited using a mouse or pointing device. A common example is content rendered by plug-ins. Plug-ins are user agents that render content inside the user agent host window and respond to all user actions that takes place while the plug-in has the focus. If the plug-in does not provide a keyboard mechanism to return focus to the parent window, users who must use the keyboard may become trapped in the plug-in content.

This problem can be avoided by using one of the following mechanisms to provide a way for users to escape the subset of the content:

  • Ensuring that the keyboard function for advancing focus within content (commonly the tab key) exits the subset of the content after it reaches the final navigation location.

  • Providing a keyboard function to move the focus out of the subset of the content. Be sure to document the feature in an accessible manner within the subset.

  • If the subset of the content does natively provide a "move to parent" keyboard command, documenting that command before the user enters the plug-in so they know how to get out again.

Examples

  • Once a user tabs into an applet, further tabs are handled by the applet preventing the person from tabbing out. However, the applet is designed so that it returns keyboard focus back to the parent window when the person finishes tabbing through the tab sequence in the applet.

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure
  1. tab through content from start to finish.

  2. check to see if keyboard focus is trapped in any of the content such that the person cannot move out of any part of the content and continue through the rest of the content.

Expected Results
  • #2 is false


G53: Identifying the purpose of a link using link text combined with link context

Applicability

All technologies that contain links.

This technique is referenced from:

Description

The objective of this technique is to identify the purpose of a link from the link and its context. This is done by associating the link with its text and with text that is associated with the immediately enclosing structural unit of the content. The purpose of the link is identified by interpreting the link in the context of the text associated with its enclosing structure unit. The description lets a user distinguish this link from links in the Web unit that lead to other destinations and helps the user determine whether to follow the link. The URI of the destination is generally not sufficiently descriptive.

Note that only the text associated with the immediately enclosing structural unit of the link is used to provide the context for the link. The definition of the immediately enclosing structural unit is technology-specific. It may not be possible to represent complex content in a way that includes all the necessary context for a link in this unit, but still represent other important relationships in the content. In this situation, another technique must be used to identify the purpose of the link.

Examples

Example 1: A list of books

A list of book titles are followed by PDF, Audible, E-book to indicate the versions available. The book title is a link to information about the book. Each version type is a link to that version of the book. Because the books are formatted as a list, each list item contains the information about a book and provides the context to understand the purpose of the book version links.

Resources

No resources available for this technique.

Tests

Procedure

For each link in the content that uses this technique:

  1. Check that text of the link combined with the text associated with the enclosing structural unit of content describes the purpose of the link

Expected Results
  • The above check is true.


G54: Including a sign language interpreter in the corner of the video stream

Applicability

Applies to all technologies that present multimedia information

This technique is referenced from:

Description

The objective of this technique is to allow users who cannot hear or read text rapidly to be able to access multimedia material.

For those who communicate primarily in sign language it is sometimes less preferable and sometimes not possible for them to read and understand text at the rate it is presented in captions. For these latter individuals it is important to provide sign language presentation of the audio information.

One universally compatible way of doing this is to simply embed a video of the sign language interpreter in the corner of the video stream. This has the disadvantage of providing a lower resolution image that cannot be easily enlarged without enlarging the entire image.

Note: Since sign language is not usually a signed version of the printed language, the author has to decide which sign language to include. Usually the sign language of the primary audience would be used. If intended for multiple audiences, multiple sign languages may be used. Refer to advisory techniques for multiple sign languages.

Examples

  • Example 1: A television station provides a sign language interpreter in the corner of its on-line news video.

Resources

  • Guidelines for the Production of Signing Books

    • "Sign Language presentation" gives a broad overview of issues to consider when filming sign language interpreters. Includes discussion of signing both written and spoken originals.

    • Techniques for filming are discussed in chapter 12, “Filming the Signer(s)”.

    • Useful information about how to display the sign language interpreter in relation to the original multimedia content is provided in Chapter 13, "Editing"

      Note: These techniques may need to be adapted for Web-based presentation.

(none currently listed)

Tests

Procedure
  1. Have someone watch the program who can hear and is familiar with the sign language being used.

  2. Check to see if there is a sign language interpreter on screen.

  3. Check to see that dialog and important sounds are being conveyed by the interpreter visible on screen.

Expected Results
  • #2 and #3 are true


G55: Linking to definitions

Applicability

All technologies that include links.

This technique is referenced from:

Description

The objective of this technique is to make the definition of a word, phrase, or abbreviation available by providing the definition, either within the same Web unit or in a different Web unit, and establishing a link between the item and its definition.

Links are a powerful option for providing access to the definition of a word, phrase, or abbreviation. A user can use the link to find the definition quickly and easily, and then return to his place in the content via the user agent's Back button.

Examples

Example 1

Technical terms and abbreviations in an article about sports injuries are linked to definitions in a medical dictionary.

Example 2

A textbook contains a glossary of new vocabulary words introduced in each chapter. The first occurrence of each of these words is linked to its definition in the glossary.

Example 3

A general glossary of abbreviations is provided. All occurrences of abbreviations are linked directly to the appropriate definition within that glossary.

Example 4

The word jargon is linked to its definition in the WCAG2 Glossary.

Example 5

The word "modulo" is jargon used in Web content about mathematics. A definition for modulo is included within the Web unit. Each occurrence of the word modulo is linked to its definition.

Example 6

A Japanese idiom is linked to its definition. This example uses a link within the page to navigate to the definition of an idiomatic expression.

<p><a href="#definition">さじを投げる</a></p>

<h3><a id="definition" name="definition">脚注:</a></h3>
<dl>
<dt>さじを投げる</dt>
<dd>どうすることもできなくなり、あきらめること。</dd>
</dl>
</p>						

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure

For each word, phrase, or abbreviation to be defined:

  1. Check that at least the first instance of the item is a link.

  2. Check that each link navigates to the definition of the item.

Expected Results
  • The checks above all pass.


G56: Mixing audio files so that non-speech sounds are at least 20 decibels lower than the speech audio content

Applicability

Any technology

This technique is referenced from:

Description

The objective of this technique is to allow authors to include sound behind speech without making it too hard for people with hearing problems to understand the speech. Making sure that the speech is 20 db louder than the backgound sound makes the speech 4 times louder than the background sounds. For information on Decibels (dB) see About Decibels

Examples

Example 1: An announcer speaking over a riot scene
  • A narrator is describing a riot scene. The volume of the riot scene is adjusted so that it is 20 db lower than the announcers volume before the scene is mixed with the narrator.

Example 2: Sufficient audio contrast between a narrator and background music

The following is a link to an mp3 file. It is an audio track that has been mixed so that there is sufficient contrast between the foreground and background. When it is listend to, the forground is heard clearly above the background.

Example of good audio contrast (MP3)

Here is a transcript of the speaking voice on this good contrast example:

"Usually the foreground refers to a voice that is speaking and should be understood. My speaking voice right now is 20 decibels above the background which is the music. This is an example of how it should be done."

Example 3 (failure): Insuficient Audio Contrast between a narrator and background music

The the following is a link to an MP3 audio example of insufficient contrast between a narrator and background music:

Example of bad audio contrast (MP3)

Here is the transcript of the voice on the insufficient contrast example:

"This is an example of a voice that is not loud enough against the background. The voice which is the foreground is only about 2 decibels above the background. Therefore is difficult to understand for a person who is hard of hearing. It is hard to discern one word from the next. This is an example of what not to do."

Example 4: Audio track that has been mixed with sufficient contrast between the foreground and background as seen in a popular audio editing program.

After the foreground and the background tracks have been mixed to one single file, that single file can be opened in any popular audio editing software package and viewed in an editing window that renders a visual representation of the audio content. This can be used to help determine the contrast level between the foreground and background of an audio track.

The graphic below (figure 1) is a visual representation of the mp3 audio file above that has sufficient contrast between the foreground and the background. Both the foreground and the background are in the selected portion of the wave file.

Figure 1
Figure 1: visual representation of sufficient contrast both foreground and background are selected.

The selected region of the wave file in figure 1 above which contains both the foreground and background sound is a very large wave. The selected region of Figure 2 below which contains only background sound is a much smaller wave.

Figure 2
Figure 2: visual representation of sufficient contrast where only the background is selected.

Resources

(none currently listed)

Tests

Procedure
  1. Locate loud values of background content between forground speech

  2. Measure the volume in dB(A) SPL

  3. Measure the volume of the forground speech in dB(A) SPL

  4. Subtract the values

  5. Check that the result is 20 or greater.

Expected Results
  • #5 is true


G57: Ordering the content in a meaningful sequence

Applicability

All technologies.

This technique is referenced from:

Description

The objective of this technique is to ensure that the order of content presented to assistive technologies allows the user to make sense of the content. Some techniques permit the content to be rendered visually in a meaningful sequence even if the underlying order of the content is confusing.

For example, when mixing languages with different directionality in HTML, the bidirectional algorithm may place punctuation in the wrong place. Correctly ordered content maintains the punctuation in the correct sequence in the content stream and uses markup to override the bidirectional algorithm, rather than moving the punctuation in the content stream so that the default rendering positions it correctly.

When rendered visually, white space characters such a space or tab may not appear to be part of the content. However, when inserted into the content to control visual formatting, they may interfere with the meaning of the content.

At a larger granularity, controlling the placement of blocks of content in an HTML document using layout tables may produce a rendering in which related information is positioned together visually, but separated in the content stream. Since layout tables are read row by row, if the caption of an illustration is placed in the row following the illustration, it may be impossible to associate the caption with the image.

Examples

Example 1

A Web page from a museum exhibition contains a navigation bar containing a long list of links. The page also contains an image of one of the pictures from the exhibition, a heading for the picture, and a detailed description of the picture. The links in the navigation bar form a meaningful sequence. The heading, image, and text of the description also form a meaningful sequence. CSS is used to position the elements on the page.

Markup:

<h1>My Museum Page</h1>
<ul id="nav">
	<li><a href="#">Link 1</a></li>
	...
	<li><a href="#">Link 10</a></li>
</ul>
<div id="description">
<h2>Mona Lisa</h2>
<p>
<img src="img.png" alt="Mona Lisa">
</p>
<p>...detailed description of the picture...</p>
</div>

CSS:

ul#nav
{
	float: left;
	width: 9em;
	list-style-type: none;
	margin: 0;
	padding: 0.5em;
	color: #fff;
	background-color: #063;
}

ul#nav a
{
	display: block;
	width: 100%;
	text-decoration: none;
	color: #fff;
	background-color: #063;
}

div#description
{
	margin-left: 11em;
}

Resources

No resources available for this technique.

Tests

Procedure
  1. Identify meaningful sequences in the source document.

  2. Check that the elements of each meaningful sequence are in consecutive order in the content.

Expected Results
  • Check #2 is true.


G58: Placing a link to the transcript immediately next to the non-text content

Applicability

This technique is not technology specific and can be used in any technology that supports links.

This technique is referenced from:

Description

With this technique, a link to the collated document of captions and audio descriptions is provided. The collated document could be at another location on the same Web unit or at another URI. A link to the collated document is immediately adjacent to the non-text content. The link can be immediately before or after the multimedia content. If the collated document is on the same Web unit as other content then put "End of document" at the end so that they know when to stop reading and return to their previous place. If a "Back" button will not take the person back to the point from which they jumped, then a link back to the non-text content location is provided.

Examples

Example 1: An .MOV Document in an HTML Document

Code on a page called "Olympic_Sports.htm"

<a name="Olympic_Wrestling"></a>
<p><a href="http://www.example.com/movies/olympic_wrestling.mov">Olympic Wrestling movie</a>, 
<a href="http://www.example.com/transcripts/olympic_wrestling_transcript.htm>Olympic 
Wrestling collated Transcript</a></p>
Example 2: The link back to the .MOV Document in an HTML Document

Code on the page olympic_wrestling_transcript.htm

<p>Sports announcer 1: This is a great battle tonight between England's "Will Johnson" and 
"Theodore Derringo" from Argentina</p>

<p>Scenery: There is a mat set out in the middle of the stadium with 500 people in the 
stands...</p>

<p> ...more dialogue ...<p>

<p> ...more scenery...</p>

<p> ...etc...</p>

<p>Sports announcer 2: And that is all for tonight, thank you for joining us tonight where 
Will Johnson is the new Gold Medalist. 
<a href="../movies/Olympic_Sports.htm#Olympic_Wrestling>Return to Movie page</a> </p>

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure
  1. Check for the presence of a link immediately before or after the non-text content

  2. Check that it is a valid link that points directly to the collated document of this particular multimedia.

  3. Check for the availability of a link or back function to get the user back to the original location of the multimedia content

Expected Results
  • Items #1 through 3 are all true.


G59: Placing the interactive elements in an order that follows sequences and relationships within the content

Applicability

All technologies that contain interactive elements and define a default tab order for interactive elements.

This technique is referenced from:

Description

The objective of this technique is to ensure that interactive elements receive focus in an order that follows sequences and relationships in the content. When designing the content, the interactive elements such as links and form controls are placed in the content so that the default tab order follows the sequences and relationships in the content. Each technology defines its default tab order, so the mechanism for placing the controls in the content will depend on the technology used.

As an example, in HTML, the default focus order follows the order in which elements appear in the content source. When the order of the HTML source matches the visual order of the Web unit, tabbing through the content follows the visual layout of the content. When the source order does not match the visual order, the tab order through the content must reflect the logical relationships in the content that are displayed visually.

Examples

  • A form contains two text input fields that are to be filled in sequentially. The first text input field is placed first in the content, the second input field is placed second.

  • A form contains two, side-by-side sections of information. One section contains information about an applicant; the other section contains information about the applicant's spouse. All the interactive elements in the applicant section receive focus before any of the elements in the spouse section. The elements in each section receive focus in the reading order of that section.

Resources

No resources available for this technique.

Tests

Procedure
  1. Determine the order of interactive elements in the content.

  2. Determine the logical order of interactive elements.

  3. Check that the order of the interactive elements in the content is the same as the logical order.

Expected Results
  • Check #3 is true.


G60: Playing a sound that turns off automatically within three seconds

Applicability

Applies to all technologies except those for spoken interaction.

This technique is referenced from:

Description

The purpose of this technique is to allow authors to play a sound on their page but avoid the problem of users not being able to use their screen readers due to interference by the content sound. It also allows the author to avoid putting controls on the page to control the sound - and the problem faced by consumers with screen readers in finding the control (when unable to hear their screen reader).

The technique is simple. The sound plays for 3 or less seconds and stops automatically.

Examples

  • Example 1: A page opens with a trumpet fanfare and then goes silent

  • Example 2: A homepage opens with a short greeting by the chairman and then goes silent.

  • Example 3: A page opens with instructions on how to use the page.

  • Example 4: A page opens with a warning and then goes silent.

Resources

(none)

(none currently listed)

Tests

Procedure
  1. open the URI

  2. check that all sound that plays automatically stops in 3 seconds or less

Expected Results
  • #2 is true


G61: Presenting repeated components in the same relative order each time they appear

Applicability

Any technologies.

This technique is referenced from:

Description

The objective of this technique is to make content easier to use by making the placement of repeated components more predictable. This technique helps maintain consistent layout or presentation between Web units by presenting components that are repeated in these Web units in the same relative order each time they appear. Other components can be inserted between them, but their relative order is not changed.

This technique also applies to navigational components that are repeated. Web units often contain a navigation menu or other navigational component that allows the user to jump to other Web units. This technique makes the placement of navigational components more predictable by presenting the links or programmatic references inside a navigational component in the same relative order each time the navigational component is repeated. Other links can be removed or inserted between the existing ones, for example to allow navigation inside a subsection of a set of Web units, but the relative order is not changed.

Examples

  • A Web site has a logo, a title, a search form and a navigation bar at the top of each page; these appear in the same relative order on each page where they are repeated. On one page the search form is missing but the other items are still in the same order.

  • A Web site has a left-hand navigation menu with links to the major sections of the site. When the user follows a link to another section of the site, the links to the major sections appear in the same relative order in the next page. Sometime links are dropped and other links are added, but the other links always stay in the same relative order. For example, on a Web site of a company that sells products and offers training, when a user moves from the section on products to the section on training, the links to individual products are removed from the navigation list, while links to training offerings are added.

Resources

(none currently listed)

Tests

Procedure
  1. List components that are repeated on each Web unit in a set of Web units (for example, on each page in a Web site).

  2. For each component, check that it appears in the same relative order with regard to other repeated components on each Web unit where it appears.

  3. For each navigational component, check that the links or programmatic references are always in the same relative order.

Expected Results
  • #2 is true.

  • #3 is true.


G62: Providing a Glossary

Applicability

Any technology containing text.

This technique is referenced from:

Description

The objective of this technique is to make the definition of a word, phrase, or abbreviation available by providing the definition in a glossary. A glossary is an alphabetical list of words, phrases, and abbreviations with their definitions. Glossaries are most appropriate when the words, phrases, and abbreviations used within the content relate to a specific discipline or technology area.

The glossary is included at the end of the Web unit or the glossary is located via one of the mechanisms for locating content within a set of Web units. (See How to Meet Success Criterion 2.4.2.)

If the glossary contains several definitions for the same word, phrase, or abbreviation, simply providing the glossary is not sufficient to satisfy this success criterion. A different technique should be used to find the correct definition. This is especially important if the uses of the word, phrase, or abbreviation are not unique within the Web unit, that is, if different occurrences of the item have different definitions.

Examples

Example 1

Users of on line chat forums have created several acronyms and abbreviations to speed up typing conversations on the computer. For example, LOL refers to "laughing out loud" and FWIW abbreviates "for what it's worth". The site provides a glossary page that lists the expansions for the commonly used acronyms and abbreviations.

Example 2

A Web unit discussing mathematical theory includes a glossary of commonly used mathematical terms, abbreviations and acronyms.

Example 3

A textbook contains a glossary of new vocabulary words introduced in each chapter.

Example 4

Dutch text uses the phrase 'Hij ging met de kippen op stok' (He went to roost with the chickens). The glossary explains that this phrase means 'Hij ging vroeg naar bed' (He went to bed early).

Example 5: A glossary of idiomatic expressions

The American novel "The Adventures of Huckleberry Finn" includes many idiomatic expressions that were used in the southwestern United States in the 1840s. In an online edition designed for students, each idiomatic expression is linked to an item in the glossary.

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure

Check that either

  1. The glossary is included in the Web unit, or

  2. A mechanism is available to locate the glossary.

For each word, phrase, or abbreviation to be defined,

  1. Check that the item is defined in the glossary, and

  2. Check that the glossary contains only one definition for each item.

Expected Results
  • All checks above pass.


G63: Providing a Site Map

Applicability

All technologies.

This technique is referenced from:

Description

A site map is a Web page that provides links to different sections of the site. To make the site map available within the site, at a minimum every page that is listed in the site map contains a link to the site map.

The site map serves several purposes.

  • It provides an overview of the entire site.

  • It helps users understand what the site contains and how the content is organized.

  • It offers an alternative to complex navigation bars that may be different at different parts of the site.

There are different types of site maps. The simplest and most common kind of site map is an outline that shows links to each section or sub-site. Such outline views do not show more complex relationships within the site, such as links between pages in different sections of the site. The site maps for some large sites use headings that expand to show additional detail about each section.

A site map describes the contents and organization of a site. It is important that site maps be updated whenever the site is updated. A Web page that does not link to all the sections of a site, that presents an organization that is different from the site's organization, or that contains links that are no longer valid is not a valid site map.

Examples

Example 1

The Web Accessibility Initiative provides a WAI site map that lists different sections of its Web site. The site map shows the different sections of the Web site, and shows some of the substructure within those sections.

Example 2

The site map for an on-line magazine lists all the sections of the magazine and the subsections in each section. It also include links for Help, How to Contact Us, Privacy Policy, Employment Opportunities, How to Subscribe, and the home page for the magazine.

Resources

  • Graphic Organizers page at the National Center for Accessible Curriculum provides a useful overview of different kinds of graphic organizers and their uses, plus a summary of relevant research on the effectiveness of graphical organizers for students with learning disabilities.

  • Usability Glossary: sitemap

Tests

Procedure
  1. Check that the site contains a site map

  2. Check that the links in the site map lead to the corresponding sections of the site

  3. For each link in the site map, check that the target page contains a link to the site map

  4. For each page in the site, check that the page can be reached by following some set of links that start at the site map.

Expected Results
  • All of the checks above are true.


G64: Providing a Table of Contents

Applicability

All technologies.

This technique is referenced from:

Description

A table of contents provides links to section headings and sub-headings within the hierarchical structure of a document.

The table of contents serves two purposes:

  • It gives users an overview of the document's contents and organization.

  • It allows readers to go directly to a specific section of an on-line document.

The table of contents typically includes only major sections of the document, though in some cases an expanded table of contents that provides a more detailed view of a complex document may be desirable.

Examples

Example 1

The Web Content Accessibility Guidelines 2.0 contains a table of contents that is a hierarchical list of links to the sections and subsections of the document. The hierarchy of the table of contents reflects the organization of the sections, and each item in the table of contents is a link that takes the user directly to that section.

Example 2

The first page of Using Accessible PDF Documents with Adobe Reader 7.0: A Guide for People with Disabilities contains a table of contents that lists the sections of the guide. The PDF version of the Guide for People with Disabilities contains a more detailed table of contents for the entire document on page 3.

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure
  1. Check that a Table of Contents or a link to a Table of Contents exists in the document.

  2. Check that the values and order of the entries in the Table of Contents correspond to the names and order of the sections of the document.

  3. Check that the entries in the Table of Contents link to the correct sections of the document.

Expected Results
  • All checks above are true.


G65: Providing a breadcrumb trail

Applicability

All technologies.

This technique is referenced from:

Description

A breadcrumb trail helps the user to visualize how content has been structured and how to navigate back to previous Web units, and may identify the current location within a series of Web units. A breadcrumb trail either displays locations in the path the user took to reach the Web unit, or it displays the location of the current Web unit within the organization of the site.

Breadcrumb trails are implemented using links to the Web units that have been accessed in the process of navigating to the current Web unit. They are placed in the same location within each Web unit in the set.

It can be helpful to users to separate the items in the breakcrumb trailing with a visible separator. Examples of separators include >, |, /, and ::.

Examples

Example 1

A developer searches within the Web site of an authoring tool manufacturer to find out how to create hyperlinks. The search results bring him to a Web unit with specific instructions for creating hyperlinks using the authoring tool. It contains the following links to create a breadcrumb trail:

Home :: Developer Center :: How To Center 

In this example the breadcrumb trail does not contain the title of the current Web unit, "How to create hyperlinks". That information is available as the title of the Web unit.

Example 2

A photographer’s portfolio Web site has been organized into different galleries and each gallery has further been divided into categories. A user who navigates through the site to a Web unit containing a photo of a Gentoo penguin would see the following breadcrumb trail at the top of the Web unit:

Home / Galleries / Antarctica / Penguins / Gentoo Penguin 

All of the items except "Gentoo Penguin" are implemented as links. The current location, Gentoo Penguin, is included in the breadcrumb trail but it is not implemented as a link.

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure

When breadcrumb trails have been implemented in a set of Web units:

  1. Navigate to a Web unit .

  2. Check that a breadcrumb trail is displayed.

  3. Check that the breadcrumb trail displays the correct navigational sequence to reach the current location or the correct hierarchical path to the current location within the site structure.

  4. For a breadcrumb trail that does not include the current location:

    1. Check that all elements in the breadcrumb trail are implemented as links.

  5. For a breadcrumb trail that does include the current location:

    1. Check that all elements except for the current location are implemented as links.

    2. Check that the current location is not implemented as a link.

  6. Check that all links navigate to the correct Web unit as specified by the breadcrumb trail.

Expected Results
  • For all Web units in the set using breadcrumb trails,

    • Checks #2, #3, and #6 are true.

    • Either check #4 or #5 is true.


G68: Providing a descriptive label that describes the purpose of live audio-only and live video-only content

Applicability

Applies to all technologies

This technique is referenced from:

Description

This technique provides a descriptive label for Live audio-only and live video-only content. This label may be used in combination with a full text transcript of the audio or a full text or audio description of the video. Those alternative however are not part of this technique. The purpose of this technique is to ensure that the user can determine what the non-text content is - even if they cannot access it. NOTE: Even if full alternatives are also available, it is important that users be able to identify the non-text content when they encounter it so that they are not confused, and so that they can associate it with the full alternative when they encounter it.

Examples

Example 1
  • A live video feed of the east coast highway has the following descriptive label "Live video picture of East Coast Highway just south of the I-81 interchange showing current traffic conditions."

  • A live audio feed of the Mississippi House of Representatives has the following descriptive label "Live audio from the microphones in the Mississippi House of Representatives."

Resources

(none currently listed)

Tests

Procedure
  1. remove, hide, or mask the non-text content

  2. display the text alternative(s)

  3. check that the purpose of the non-text content is clear - even if content is lost.

Expected Results
  • #3 is true.


G69: Providing a full multimedia text alternative including any interaction

Applicability

General technique. Applies to all technologies

This technique is referenced from:

Description

The purpose of this technique is to provide an accessible alternative way of presenting the information in a multimedia presentation.

In a multimedia presentation, information is presented in a variety of ways including

  • dialogue,

  • sounds (natural and artificial),

  • the setting and background,

  • the actions and expressions of people, animals, etc.,

  • text or graphics,

  • and more.

In order to present the same information in accessible form, this technique involves creating a document that tells the same story and presents the same information as the multimedia. Such a document is sometimes called a screenplay. It includes all the important dialogue and actions as well as descriptions of backgrounds etc. that are part of the story.

If an actual screenplay was used to create the multimedia in the first place, this can be a good place to start. In production and editing however, the multimedia usually changes from the screenplay. For this technique, the original screenplay would be corrected to match the dialogue and what actually happens in the final edited form of the multimedia.

In addition, some special types of multimedia include interaction that has to occur at particular places in the playing of the multimedia. Sometimes it may result in an action taking place (e.g. something is purchased, sent, done, etc.). Sometimes it may change the course of the multimedia (e.g. the multimedia has multiple paths that are determined by user input). In those cases links or some other mechanism would be used in the full multimedia text alternative to allow people using the alternative to be able to have the same options and abilities as those using the multimedia.

Examples

  • A training film shows employees how to use a new piece of equipment. It involves a person talking throughout while they demonstrate the operation. The screenplay used to create the training film is used as a starting point. It is then edited and corrected to match the dialogue etc. The film and the resulting full multimedia text alternative are then made available on the company Web site. Employees can then use either or both to learn how to use the machine.

  • An interactive shopping environment is created that allows users to steer themselves around in a virtual store and shop. A full multimedia text alternative allows the users to access the same shopping in text with links to choose aisles and to purchase things instead of dragging them into a virtual shopping basket.

Resources

No resources available for this technique.

Tests

Procedure
  1. View the multimedia presentation with the full multimedia text alternative in hand.

  2. Check that the dialogue in the full multimedia text alternative matches the dialogue in the multimedia presentation

  3. Check that full multimedia text alternative has descriptions of sounds.

  4. Check that full multimedia text alternative has descriptions of setting and setting changes.

  5. Check that full multimedia text alternative has descriptions of actions and expressions of any 'actors' (people, animals etc).

Expected Results
  • #2, 3, 4, 5 are true.


G70: Providing a function to search an on-line dictionary

Applicability

All technologies

This technique is referenced from:

Description

The objective of this technique is to provide the definition of words, phrases, jargon, or abbreviation expansions by adding a mechanism to access an on-line dictionary to the Web unit. This technique uses existing resources on the Web to provide the definition rather than requiring the author to create a glossary or other mechanism within the site. By providing access from within the Web unit, a user can easily locate the desired definition.

Examples

Example 1

A site that describes how a computer works would include a search form on each Web unit. The search would be performed against an on-line dictionary of computer terms, acronyms, and abbreviations. Since the dictionary is specialized for computer terms, the acronym expansion found should be more accurate than with a general dictionary.

Example 2

An on-line course in English grammar provides a paragraph of text which introduces new vocabulary words. Each of the vocabulary words is a link to an on-line dictionary to find the definition of the word. Activating a link will open up a new window to an on-line dictionary site with the specific vocabulary word defined.

An on-line course in English grammar provides a paragraph of text which introduces new vocabulary words. Each of the vocabulary words is a link to an on-line dictionary to find the definition of the word. Activating a link will open up a new window to an on-line dictionary site with the specific vocabulary word defined.

Resources

No resources available for this technique.

Tests

Procedure

For each word, phrase, or abbreviation to be defined:

  1. Check that a mechanism exists within the Web unit to search for the word, phrase, or abbreviation via an on-line dictionary.

  2. Check that a search of the dictionary for the word, phrase, or abbreviation finds the correct definition.

Expected Results
  • Checks #1 and #2 are true.


G71: Providing a help link on every Web unit

Applicability

All technologies.

This technique is referenced from:

User Agent and Assistive Technology Support Notes

The example following does not work with JAWS—implicit labels are poorly supported, and JAWS does not read the Help link as part of the label before announcing the control (as required by the SC).

Description

The objective of this technique is to provide context sensitive help for users as they enter data in forms by providing at least one link to the help information on each Web unit. The link targets a help page with information specific to that Web unit. Another approach is to provide a help link for every interactive control. Positioning this link immediately before or after the control allows users to easily tab to it if they have problems in the control. Displaying the help information in a new browser window ensures that any data that has already been entered into the form will not be lost. NOTE: A link is not the only means to provide help.

Examples

Example 1

The example below shows a label element enclosing both an input form control, and a help link following the "input" in sequence. Including the help link within the label element allows screen reader users to have access to the help link when interacting with the input form control.

<form action="test.html">
	<label for="test">Test control
	<input type="text" name="test" id="test" />
	<a href="help.html" target="_blank">Help</a></label>
</form>

Tests

Procedure
  1. Identify a Web unit that contains forms.

  2. Determine if there is at least one link to help information specific to completing the form on this Web unit or other resource.

  3. Determine if there are links either before or after each interactive control to help information specific to that control.

Expected Results
  • Either #2 or #3 are true.


G73: Providing a long description in another location with a link to it that is immediately adjacent to the non-text content

Applicability

Applies to all technologies

This technique is referenced from:

Description

The objective of this technique is to provide a way to link to remote long descriptions in technologies that do not have a long description feature built directly into them (e.g. longdesc) or where the feature is known to not be supported.

With this technique, the long description is provided in another location than the non-text content. This could be at another location within the same URI or at another URI. A link to that long description is provided that is immediately adjacent to the non-text content. The link can be immediately before or after the non-text content. If the description is located along with other text then put "End of description" at the end so that they know when to stop reading and return to the main content. If a "Back" button will not take the person back to the point from which they jumped, then a link back to the non-text content location is provided.

This technique was commonly used in HTML before 'longdesc' was added to the specification. In HTML it was called a D-Link because it was usually implemented by putting a D next to images and using the D as a link to the long description. This technique is not technology specific and can be used in any technology that supports links.

Examples

Example 1: Bar chart

There is a bar chart on a Web page showing the sales for the top three salespeople.

The short text alternative says "October sales chart for top three salespeople."

Immediately after the non-text content is a small image denoting a long description. The alternate text for the image is "Long description of chart". The image links to the bottom of the page where there is a section titles "Description of charts on this page". The link points to this specific description: " Sales for October show Mary leading with 400 units. Mike follows closely with 389. Chris rounds out our top 3 with sales of 350. [end of description]"

Example 2: Bar chart - in non-HTML technology where user agent "back" is not supported for security reasons.

There is a bar chart on a Web page showing the sales for the top three salespeople.

The short text alternative says "October sales chart for top three salespeople."

Immediately after the non-text content is a small image denoting the long description. The alternate text for the image is "Long description of chart". The image links to another page titled "Description of charts in October Sales Report". The description link points to this specific description: "Sales for October show Mary leading with 400 units. Mike follows closely with 389. Chris rounds out our top 3 with sales of 350. End of description. <link> Back to Sales Chart </link> ]"

Example 3: Caption used as link

There is a chart. The figure caption immediately below the chart serves as a link to the long description. The Title attribute of the link makes it clear that this is a link to a long description.

Example 4: Transcript of an audio-only file

There is a recording of a speech by Martin Luther King. Links to the audio file and the transcript appear side by side.

Resources

(none currently listed)

Tests

Procedure
  1. check for the presence of a link immediately before or after the non-text content

  2. check that the link is a valid link that points directly to the long description of this particular non-text content.

  3. check that the long description conveys the same information as the non-text content

  4. check for the availability of a link or back function to get the user back to the original location of the non-text content

Expected Results

All 4 of the above are true


G74: Providing a long description in text near the non-text content, with a reference to the location of the long description in the short description

Applicability

Applies to all technologies

This technique is referenced from:

Description

The objective of this technique is to provide a long description without requiring the user to jump off to another location for the description. It also allows all users to see the description which may be useful to anyone who might miss some features in the non-text content.

With this technique, the long description is provided as part of the standard presentation (i.e. everyone receives it). The description is located near the non-text content but does not have to be the very next item. For example, there may be a caption under a chart with the long description provided in the following paragraph.

The location of this long description is then provided within the short text alternative so the user knows where to look for it if they cannot view the non-text content.

Examples

Example 1: Bar chart

There is a bar chart on a Web page showing the sales for the top three salespeople.

The short text alternative says: "October sales chart for top three salespeople. Details in text following the chart:"

The following is in the paragraph immediately below the chart. " Sales for October show Mary leading with 400 units. Mike follows closely with 389. Chris rounds out our top 3 with sales of 350"

Resources

(none currently listed)

Tests

Procedure
  1. check that the short text alternative includes the location of the long description

  2. Check that the long description is near the non-text content both visually and in the linear reading order

  3. check that the long description conveys the same information as the non-text content

Expected Results

All 3 of the above are true


G75: Providing a mechanism to postpone any updating of content

Applicability

Content that automatically updates itself.

This technique is referenced from:

Description

The objective of this technique is to ensure that users can postpone automatic updates of content, or other non-emergency interruptions. This can be accomplished either through a preference or by alerting users of an imminent update and allowing them to suppress it. If a preference is provided, automatic content update can be disabled by default and users can specify the frequency of automatic content updates if they choose to enable the setting.

Examples

  • A Web page provides stock quotes and automatically updates from time to time. The page provides a short form with a field "Refresh data frequency (minutes):" so users can adjust the frequency of the updating.

Tests

Procedure
  1. Find pages with content that automatically updates.

  2. For each automatic update, look for a mechanism to adjust the timing of the updates.

  3. Check that automatic updating is disabled by default or that the user is warned before an automatic update occurs and allowed to suppress it.

Expected Results
  • #3 is true.


G76: Providing a mechanism to request an update of the content instead of updating automatically

Applicability

Any technology or combination of technologies that support automatic updates.

This technique is referenced from:

Description

The objective of this technique is to let the user control if and when content is updated, in order to avoid confusion or disorientation caused by automatic refreshes that cause a change of context. Users of screen readers may find automatic updates confusing because it is not always clear what is happening. When a page is refreshed, the screen reader's “virtual cursor”, which marks the user's current location on the page, is moved to the top of the page. People who use screen magnification software and people with reading disabilities may also be disoriented when pages are refreshed automatically.

Some content is frequently updated with new data or information. Some developers force automatic updates by inserting code in the content that causes the content to request a new copy of itself from the server. These updates and the frequency of these updates are not always under the user's control. Instead of triggering updates automatically, authors can provide a mechanism that allows the user to request an update of the content as needed.

Examples

Example 1

In HTML, a developer can provide a button or link that allows the user to update the content. For example, on a page with news items located at http://www.example.com/news.jsp

<a href="news.jsp">Update this page</a>
Example 2

In a Web interface for e-mail (Webmail), a developer can provide a button or link to fetch new incoming mails instead of updating automatically.

Resources

  • Time outs and page refreshes, by the Web Access Centre of the Royal National Institute of the Blind (RNIB), provides rationale and techniques.

(none currently listed)

Tests

Procedure
  1. Find mechanisms to update the content (if such a mechanism is present).

  2. For each such mechanism, check if it allows the user to request an update.

  3. For each such mechanism, check if it can cause an automatic update.

Expected Results
  • If #2 is true, then #3 is false.


G78: Providing a sound track that includes audio description

Applicability

Applies to any technology that has a sound track and visual content.

This technique is referenced from:

Description

The objective of this technique is to provide an audio (spoken) version of information that is provided visually so that it is possible for people who cannot see to be able to understand audio-visual material better.

Since most user agents today cannot merge multiple sound tracks, this technique adds the additional audio information to multimedia by replacing the soundtrack with a new copy of the original soundtrack that has the additional audio descriptions added. This added information focuses on actions, characters, scene changes and on-screen text (not captions) that are important to understanding the content.

Since it is not helpful to have this new information obscure key audio information in the original sound track (or be obscured by loud sound effects) the new information is added during pauses in dialog and sound effects. This limits the amount of supplementary information that can be added to program.

The soundtrack with the audio descriptions (of visual information) can either be an alternate sound track that the user can choose, or it can be the standard sound track that everyone hears.

Examples

Example 1

Example 1: A travelogue of the northeast has additional audio descriptions added during the gaps in the dialog to let listeners who are blind know what the person is talking about at any point in time.

Example 2: A lecture has audio description added when the instructor says things like "and this is the one that is most important" to let listeners who are blind know what "this" is.

Example 3: A movie file has two audio tracks, one of which has audio descriptions. Users can choose either one when listening to the movie.

Resources

(none currently listed)

Tests

Procedure
  1. Select audio track with descriptions if there is a choice of audio tracks

  2. Listen to the movie

  3. Check to see if gaps in dialog are used to convey important information regarding visual content

Expected Results
  • #3 is true


G79: Providing a spoken version of the text

Applicability

Technologies that support links, audio formats.

This technique is referenced from:

Description

Some users who have difficulty sounding out (decoding) words in written text find it very helpful to hear the text read aloud. This service can now be provided easily using either recorded human speech or synthetic speech. For example, there are a number of products that authors can use to convert text to synthetic speech, then save the spoken version as an audio file. A link to the spoken version can then be provided within the content. Cost depends in part on the quality of the voice used and whether the text is likely to change frequently.

  • Spoken versions of short texts and static text content

    This method is effective for small amounts of text and for longer documents that do not change often.

    1. Make a recording of someone reading the text aloud, or use a tool that converts individual documents or selected passages into synthetic speech. Choose the clearest, most attractive voice if a choice is available.

    2. Save the spoken version as an audio file. Use an audio format that is widely available and supported by media players.

    3. Provide a link to the audio version.

    4. Identify the audio format (for example, .MP3, .WAV, .AU, etc.).

    5. Provide a link to a media player that supports the format.

  • Spoken versions of text that changes

    Server-based methods may be best when pages change often or when user choice determines text content. Some server-based tools allow users to select any text they are interested in and listen to it. Typically, the user presses a button which starts the text-to-speech conversion and reads the text aloud.

Examples

Example 1: A Web site for a government agency

The Web site for a municipal housing authority has a button on every page labeled "Read this page aloud." The user selects the button and the page is spoken by a synthetic voice.

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure
  1. Check if a spoken version of the content is available.

Expected Results
  • Check #1 is true.


G80: Providing a submit button to initiate a change of context

Applicability

Content that includes forms.

This technique is referenced from:

Description

The objective of this technique is to provide a mechanism that allows users to explicitly request changes of context. Since the intended use of a submit button is to generate an HTTP request that submits data entered in a form, this is an appropriate control to use for causing a change of context and is a practice that does not create confusion for users.

Examples

Example 1

Example 1: A submit button is used for each form that causes a change in context.

Resources

Tests

Procedure
  1. Find all forms in the content

  2. For each form, check that it has a submit button

Expected Results
  • #2 is true


G81: Providing a synchronized video of the sign language interpreter that can be displayed in a different viewport or overlaid on the image by the player

Applicability

Applies to all multimedia technologies that allow synchronization of multiple video streams

This technique is referenced from:

Description

The objective of this technique is to allow users who cannot hear or read text rapidly to be able to access multimedia material without affecting the presentation of the material for all viewers.

For those who communicate primarily in sign language it is sometimes less preferable and sometimes not possible for them to read and understand text at the rate it is presented in captions. For these latter individuals it is important to provide sign language presentation of the audio information.

This technique accomplishes this by providing the sign language interpretation as a separate video stream that is synchronized with the original video stream. Depending on the player, this secondary video stream can be overlaid on top of the original video or displayed in a separate window. It may also be possible to enlarge the sign language interpreter separately from the original video to make it easier to read the hand, body and facial movements of the signer.

NOTE: Since sign language is not usually a signed version of the printed language, the author has to decide which sign language to include. Usually the sign language of the primary audience would be used. If intended for multiple audiences, multiple languages may be used. See advisory technique for multiple sign languages.

Examples

Example 1

Example 1: A university provides a synchronized sign language interpreter video stream that can be displayed, at the viewer's option, along with any of their education programs.

Resources

  • Guidelines for the Production of Signing Books

    • ”Sign Language presentation” gives a broad overview of issues to consider when filming sign language interpreters. Includes discussion of signing both written and spoken originals.

    • Techniques for filming are discussed in chapter 12, “Filming the Signer(s)”.

    • Useful information about how to display the sign language interpreter in relation to the original multimedia content is provided in Chapter 13, "Editing".

      Note: These techniques may need to be adapted for Web-based presentation.

(none)

(none currently listed)

Tests

Procedure
  1. Enable the display of the sign-language window in the player.

  2. Have someone watch the program who can hear and is familiar with the sign language being used.

  3. Check to see if there is a sign language interpreter on screen or in a sparate window.

  4. Check to see that dialog and important sounds are being conveyed by the interpreter and are synchronized with the audio.

Expected Results
  • #3 and #4 are true


G82: Providing a text alternative that identifies the purpose of the functional non-text content

Applicability

Applies to all technologies

This technique is referenced from:

Description

The purpose of this technique is to provide useful information via the text alternative even if the full function of the non-text content cannot be provided.

Sometimes, a text alternative cannot serve the same purpose as the original non-text content (for example an applet meant to develop two dimensional rapid targeting skills and eye hand coordination.) In these cases this technique is used. With this technique a description of the purpose of the non-text content is provided.

Examples

Example 1
  • An eye-hand coordination development applet has the following text alternative "Applet that uses the mouse and moving targets to develop eye-hand coordination"

  • A camera applet that has a round disk where you push on the edges to control a remote camera and a slider in the middle for zooming has the following text alternative "Control for aiming and zooming remote video camera".

Resources

(none currently listed)

Tests

Procedure
  1. remove, hide, or mask the non-text content

  2. replace it with the text alternative

  3. check that the purpose of the non-text content is clear - even if function is lost.

Expected Results
  • #3 is true.


G83: Providing a text message that identifies the field as mandatory

Applicability

Content that includes mandatory fields in user input

This technique is referenced from:

Description

The objective of this technique is to notify the user when a field that must be completed has not been completed. When users fail to provide input for any mandatory form fields, information is provided in text to enable the users to identify which fields were omitted. One approach is to use client-side validation and provide an alert dialog box identifying the mandatory fields which were omitted. Another approach, using server-side validation, is to re-display the form (including any previously entered data), with either a text description at the location of the omitted mandatory field, or a text description that identifies the omitted mandatory fields.

Examples

  • A user attempts to submit a form but has neglected to provide input or select a choice in one or more mandatory fields. Using client-side validation, the omission is detected and an alert dialog appears informing the user that mandatory fields have not been completed. The labels of the fields with this problem are changed to identify the problem field, and links to the problem fields are inserted in the document after the submit button so the user can move to them after dismissing the alert.

  • A user attempts to submit a form but has neglected to provide input or select a choice in one or more mandatory fields. Using server-side validation, the omission is detected and the form is re-displayed with a text message at the top informing which mandatory fields were omitted. Each omitted mandatory field is also identified using a text label so that the user does not have to return to the list at the top of the form to find the omitted fields.

  • A user is completing a form that contains mandatory fields. The labels of the fields indicate whether or not they are mandatory. The user tabs to a mandatory field, and tabs out of the field without entering any data or selecting a choice. A client-side script modifies the label of the field to indicate that leaving it blank was an error.

Tests

Procedure
  1. Fill out a form, deliberately leaving one or more required (mandatory) fields blank, and submit it.

  2. Check that a text message is provided identifying the mandatory field(s) that was not completed.

Expected Results
  • #2 is true


G84: Providing a text message when the user provides information that is not in list of allowed values

Applicability

Content that collects user input where a limited set of values must be input.

This technique is referenced from:

Description

When users enter input that is validated, and errors are detected, the nature of the error needs to described to the user in manner they can access. One approach is to present an alert dialog that describes fields with errors when the user attempts to submit the form. Another approach, if validation is done by the server, is to return the form (with the user's data still in the fields) and a text description at the top of the page that indicates the fact that there was a validation problem, describes the nature of the problem, and provides ways to locate the field(s) with a problem easily. The "in text" portion of the success criterion underscores that it is not sufficient simply to indicate that a field has an error by putting an asterisk on its label or turning the label red. A text description of the problem should be provided.

When input must be one of a set of allowed values, the text message should indicate this fact. It should include the list of values if possible, or suggest the allowed value that is most similar to the entered value.

Examples

  • The user inputs invalid data on a form field. Before the user submits the form, an alert dialog appears that describes the nature of the error so the user can fix it.

  • The user inputs invalid data on a form field and submits the form. The server returns the form, with the user's data still present, and indicates clearly in text at the top of the page that there were validation errors. The text describes the nature of the error(s) and clearly indicates which field had the problem so the user can easily navigate to it to fix the problem.

Tests

Procedure
  1. Enter invalid data in a form field.

  2. Check that information is provided in text about the problem.

Expected Results
  • #2 is true.


G85: Providing a text message when user input falls outside the required format or values

Applicability

Content that accepts user data input, with restrictions on the format, value, and/or type of the input.

This technique is referenced from:

Description

The objective of this technique is to provide assistance in correcting input errors where the information supplied by the user is not accepted as valid. When users enter data input that is validated, and input errors are detected, information about the nature and location of the input error is provided in text to enable the users to identify the problem. One approach is to use client-side validation and provide an alert dialog box that describes the error immediately when users enter invalid data in field. Another approach, using server-side validation, is to re-display the form (including any previously entered data), and a text description at the top of the page that indicates the fact that there was a validation problem, describes the nature of the problem, and provides ways to easily locate the field(s) with a problem.

However the text message is provided, it should do one of the following things to assist the user:

  • Provide examples of the correct data entry for the field,

  • Describe the correct data entry for the field,

  • Show values of the correct data entry that are similar to the user's data entry, with instructions to the user as to how to enter one of these correct values should the user choose to do so.

Examples

  • The user inputs invalid data on a form field. When the user exits the field, an alert dialog appears that describes the nature of the error so the user can fix it.

  • The user inputs invalid data on a form field and submits the form. The server returns the form, with the user's data still present, and indicates clearly in text at the top of the page that there were validation errors. The text describes the nature of the error(s) and clearly indicates which field had the problem so the user can easily navigate to it to fix the problem.

  • The user inputs invalid data on a form field and attempts to submit the form. Client side scripting detects the error, cancels the submit, and modifies the document to provide a text message after the submit button describing the error, with links to the field(s) with the error. The script also modifies the labels of the fields with the problems to highlight them.

Tests

Procedure
  1. Fill out a form, deliberately leaving a required (mandatory) field blank, and submit it.

  2. Check that a text message is provided that identifies the field in error and provides some information about the nature of the invalid entry and how to fix it.

Expected Results
  • #2 is true


G86: Providing a text summary that requires reading ability less advanced than the upper secondary education level

Applicability

All technologies.

This technique is referenced from:

Description

The objective of this technique is to provide a summary of content that is difficult to read. The summary is provided in addition to the original content.

Users with disabilities that make it difficult to decode words and sentences are likely to have trouble reading and understanding complex text. This technique provides a short statement of the most important ideas and information in the content. The summary is easier to read because it uses shorter sentences and more common words than the original.

The following steps can be used to prepare the summary:

  1. Identify the most important ideas and information in the content.

  2. Write one or more paragraphs that use shorter sentences and more common words to express the same ideas and information. (The number of paragraphs depends on the length of the original.)

  3. Measure the readability of the summary.

  4. Edit the summary. Consider dividing longer sentences into two or replacing long or unfamiliar words with shorter, more common terms.

  5. Repeat steps 3 and 4 as needed.

Examples

Example 1: A technical article with a readable summary

An article describes a technical innovation. The first item after the title of the article is a section with the heading, “Summary.” The average length of the sentences in the summary is 16 words (compared to 23 words for sentences in the article), and it uses short, common words instead of the technical jargon in the article. A readability formula is applied; the summary requires reading ability less advanced than the lower secondary education level.

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure

For each summary provided as supplemental content:

  1. Measure the readability of the summary.

  2. Check that the summary requires reading ability less advanced than the lower secondary education level.

Expected Results
  • All checks pass.


G87: Providing closed captions

Applicability

Any audiovideo technology where there are user agents that support closed captions.

This technique is referenced from:

Description

The objective of this technique is to provide a way for people who have hearing impairments or otherwise have trouble hearing the dialog in multimedia material to be able to view the material and see the dialog and sounds - without requiring people who are not deaf to watch the captions. With this technique all of the dialog and important sounds are embedded as text in a fashion that causes the text not to be visible unless the user requests it. As a result they are visible only when needed. This requires special support for captioning in the user agent.

NOTE: Captions should not be confused with subtitles. Subtitles provide text of only the dialog and do not include important sounds.

Examples

Example 1

Example 1: In order to ensure that users who are deaf can use their interactive educational materials, the college provides captions and instructions for turning on captions for all of their audio interactive educational programs.

Example 2: The online movies at a media outlet are all include captions and are provided in a format that allows embedding of closed captions.

Example 3: Special caption files including synchronization information are provided for an existing movie. Players are available that can play the captions in a separate window on screen, synchronized with the movie window.

Example 4: A video of a local news event has captions provided that can be played over the video or in a separate window depending on the player used.

Resources

Tests

Procedure
  1. Turn on the closed caption feature of the media player

  2. View the multimedia content

  3. Check that captions (of all dialog and important sounds) are visible

Expected Results
  • #3 is true


G88: Providing descriptive titles for Web units

Applicability

All technologies.

This technique is referenced from:

Description

The objective of this technique is to give each Web unit a descriptive title. Descriptive titles help users find content, orient themselves within it, and navigate through it. The title can be used to identify the Web unit without requiring users to read or interpret page content. Users can more quickly identify the content they need when accurate, descriptive titles appear in site maps or lists of search results. When descriptive titles are used within link text, they help users navigate more precisely to the content they are interested in.

These techniques benefit all users. They are especially helpful for users with disabilities that make reading slow, and for people with limited short-term memory. People who have difficulty using their hands or who experience pain when doing so will benefit from techniques that reduce the number of keystrokes required to reach the content they need.

The title of each Web unit that can be accessed separately should:

  • Identify the subject of the Web unit

  • Make sense when read out of context, for example by a screen reader or in a site map or list of search results

  • Be short

It may also be helpful for the title to

  • Identify the site or other resource to which the Web unit belongs

Examples

Example 1: A title that lists the most important identifying information first

A Web unit is published by a group within a larger organization. The title of the Web unit first identifies the topic of the page, then shows the group name followed by the name of the parent organization.

<title>Working with us: The Small Group: The Big Organization</title>
Example 2: A multimedia presentation with a descriptive title

A multimedia presentation about the 2004 South Asian tsunami is titled “The Tsunami of 2004.”

Example 3: A Web unit with a descriptive title in three parts

A Web unit provides guidelines and suggestions for creating closed captions. The Web unit is part of a “sub-site” within a larger site. The title is separated into three parts by dashes. The first part of the title identifies the organization. The second part identifies the sub-site to which the Web unit belongs. The third part identifies the Web unit itself. (For a working example, see WGBH – Media Access Group – Captioning FAQ.)

Resources

No resources available for this technique.

Tests

Procedure
  1. Check that the Web unit has a title

  2. Check that the title describes the content of the Web unit.

  3. Check that the content of the Web unit can be identified using only the title.

Expected Results
  • All checks above are true.


G89: Providing expected data format and example

Applicability

Pages that collect information from users, and restrict the format the user can use.

This technique is referenced from:

Description

The objective of this technique is to help the user avoid input errors by informing them about restrictions on the format of data that they must enter. This can be done by describing characteristics of the format or providing a sample of the format the data should have.

Note: For data formats with common variations, such as dates and times, it may be useful to provide a preference option so users can use the format that is most comfortable to them.

Examples

Example 1

The following HTML form control for a date indicates in the label that the date must be in day-month-year format, not month-day-year as many users in the United States may assume.

<label for="date">Date (dd-mm-yyyy)</label>
<input type="text" name="date" id="date" />

Tests

Procedure
  1. Identify form controls that will only accept user input data in a given format.

  2. Determine if each of the form controls identified in 1 provides information about the expected format.

Expected Results
  • #2 is true.


G90: Providing keyboard-controllable event handlers

Applicability

Applies to all technologies where content includes functionality.

This technique is referenced from:

Description

The objective of this technique is to permit individuals who rely on a keyboard or keyboard interface to access the functionality of the content. To do this, make sure that all of the events used in scripts or other interactive controls on the page are associated with a keyboard-based event, or provide redundant keyboard-based mechanisms to accomplish the functionality provided by other device-specific functions.

Examples

  • Example 1: A drag and drop featureA photo application includes a "drag" and "drop" feature to allow users to re-order photographs in an on-line album for presentation as a slide show. It also includes a feature that allows users to select a photo and 'cut' and 'paste' the items into the list at the appropriate point using only the keyboard.

  • Example 2: A reorder feature A Web application that allows users to create surveys by dragging questions into position includes a list of the questions followed by a text field that allows users to re-order questions as needed by entering the desired question number.

Resources

No resources available for this technique.

Tests

Procedure
  1. check that all functionality can be accessed using only the keyboard

Expected Results
  • #1 is true


G91: Providing link text that describes the purpose of a link

Applicability

All technologies that contain links.

This technique is referenced from:

Description

The objective of this technique is to describe the purpose of a link in the text of the link. The description lets a user distinguish this link from links in the Web unit that lead to other destinations and helps the user determine whether to follow the link. The URI of the destination is generally not sufficiently descriptive.

Examples

Example 1: Describing the purpose of a link in HMTL in the text content of the a element
<a href="routes.html">
  Current routes at Boulders Climbing Gym
</a>

Resources

No resources available for this technique.

Tests

Procedure

For each link in the content that uses this technique:

  1. Check that text of the link describes the purpose of the link

Expected Results
  • The above check is true.


G92: Providing long description for non-text content that serves the same purpose and presents the same information

Applicability

Applies to all technologies

This technique is referenced from:

Description

The objective of this technique is to provide a long text alternative that serves the same purpose and presents the same information as the original non-text content when a short text alternative is not sufficient.

Combined with the short text alternative, the long description should be able to substitute for the non-text content. The short alternative identifies the non-text content; the long alternative provides the information. If the non-text content were removed from the page and substituted with the short and long descriptions, the page would still provide the same function and information.

In deciding what should be in the text alternatives, the following questions are helpful.

  • Why is this non-text content here?

  • What information is it presenting?

  • What purpose does it fulfill?

  • If I could not use the non-text content, what words would I use to convey the same function and/or information?

Examples

Example 1

A chart showing sales for October has a short text alternative of "October sales chart". The long description would read "Bar Chart showing sales for October. There are 6 salespersons. Maria is highest with 349 units. Frances is next with 301. Then comes Juan with 256, Sue with 250, Li with 200 and Max with 195. The primary use of the chart is to show leaders, so the description is in sales order."

Example 2

A line graph that shows average winter temperatures from the past 10 years includes a short text alternative of "Average winter temperatures 1996-2006." The long description includes the data table that was used to generate the line graph.

Resources

Tests

Procedure
  1. Remove, hide, or mask the non-text content

  2. Display the long description

  3. Check that the long description conveys the same information conveyed by the non-text content.

Expected Results
  • #3 is true.


G93: Providing open captions that are embedded directly in the video stream

Applicability

Any multimedia technology, even ones that do not support closed captions.

This technique is referenced from:

Description

The objective of this technique is to provide a way for people who are deaf or otherwise have trouble hearing the dialog in audio visual material to be able to view the material. With this technique all of the dialog and important sounds are embedded as text in the video track. As a result they are always visible and no special support for captioning is required by the user agent.

NOTE: Captions should not be confused with subtitles. Subtitles provide text of only the dialog and do not include important sounds.

Examples

  • In order to ensure that everyone can view their online movies, even if users do not know how to turn on captions in their media player, a library association puts the captions directly into the video.

  • A news organization provides open captions on all of its material.

Resources

(none listed)

Tests

Procedure
  1. Watch the multimedia with closed captioning turned off.

  2. Check that captions (of all dialog and important sounds) are visible.

Expected Results
  • #2 is true


G94: Providing short text alternative for non-text content that serves the same purpose and presents the same information as the non-text content

Applicability

Applies to all technologies.

This technique is referenced from:

Description

The objective of this technique is to create a text alternative that serves the same purpose and presents the same information as the original non-text content. As a result, it is possible to remove the non-text content and replace it with the text alternative and no functionality or information would be lost. This text alternative should not necessarily describe the non-text content. It should serve the same purpose and convey the same information. This may sometimes result in a text alternative that looks like a description of the non-text content. But this would only be true if that was the best way to serve the same purpose.

If possible, the short text alternative should completely convey the purpose and information. If it is not possible to do this in a short phrase or sentence, then the short text alternative should provide a brief overview of the information. A long text alternative would be used in addition to convey the full information.

The text alternative should be able to substitute for the non-text content. If the non-text content were removed from the page and substituted with the text, the page would still provide the same function and information. The text alternative would be brief but as informative as possible.

In deciding what text to include in the alternative, it is a often a good idea to consider the following questions:

  • Why is this non-text content here?

  • What information is it presenting?

  • What purpose does it fulfill?

  • If I could not use the non-text content, what words would I use to convey the same function and/or information?

Examples

  • A search button uses an image of a magnifying glass. The text alternative is "search" and not "magnifying glass".

  • A picture shows how a knot is tied including arrows showing how the ropes go to make the knot. The text alternative describes how to tie the knot, not what the picture looks like.

  • A picture shows what a toy looks like from the front. The text alternative describes a front view of the toy.

  • An animation shows how to change a tire. A short text alternative describes what the animation is about. A long text alternative describes how to change a tire.

  • A logo of the TechTron company appears next to each product in a list that is made by that and has a short text alternative that reads, "TechTron."

  • A chart showing sales for October has an short text alternative of "October sales chart". It also has a long description that provides all of the information on the chart.

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure
  1. remove, hide, or mask the non-text content

  2. replace it with the text alternative

  3. check that nothing is lost (the purpose of the non-text content is met by the text alternative)

Expected Results
  • Step 3 is true.


G95: Providing short text alternatives that provide a brief description of the non-text content

Applicability

Applies to all technologies

This technique is referenced from:

Description

This technique is used when the text needed to serve the same purpose and present the same information as the original non-text content is too lengthy or when this goal cannot be achieved with text alone. In that case this technique is used to provide a short text alternative that briefly describes the non-text content. (A long text alternative is then provided using another technique such that the combination serves the same purpose and presents the same information as the original non-text content.)

In deciding what text to include in the alternative, it is often a good idea to consider the following questions:

  • Why is this non-text content here?

  • What information is it presenting?

  • What purpose does it fulfill?

  • If I could not use the non-text content, what words would I use to convey the same function and/or information?

Examples

  • A chart showing sales for October has an short text alternative of "October sales chart". It also has a long description that provides all of the information on the chart.

Resources

Tests

Procedure
  1. Check for the presence of a short text alternative that provides a brief description of the non-text content.

Expected Results
  • #1 and #2 are true.


G96: Providing textual identification of items that otherwise rely only on shape and/or position to be understood

Applicability

All technologies that allow the creation of various shaped objects and backgrounds or allow objects to be explicitly positioned within the Web unit.

This technique is referenced from:

Description

The objective of this technique is to ensure that items within a Web unit are referenced in the content not only by shape, size or location, but also in ways that do not depend on visual perception. For example, a reference may also describe the function of the item or its label.

Examples

Example 1

A round button is provided on a form to submit the form and move onto the next step in a progression. The button is labeled with the text "go." The instructions state, "to submit the form press the round button labeled go". This includes both shape and textual information to locate the button.

Example 2

Instructions for a Web unit providing on-line training state, "Use the list of links to the right with the heading, "Class Listing" to navigate to the desired on-line course." This description provides location as well as textual clues to help find the correct list of links.

Example 3

The following layout places a button in the lower right corner and indicates it by position. An indication of the text label clarifies which button to use for users who access a linearized version in which the position is not meaningful.

<table>
  <tbody>
    <tr>
      <td colspan="2">Push the lower right [Preview] button.</td>
      <td>
        <span style="background: ButtonFace; color: ButtonText; border: 
        medium outset ButtonShadow; 
        width: 5em; display: block; font-weight: bold; text-align: center;">
        Print</span>
      </td>
    </tr>
    <tr>
      <td>
        <span style="background: ButtonFace; color: ButtonText; border: 
        medium outset ButtonShadow; 
        width: 5em; display: block; font-weight: bold; text-align: center;">
        Cancel</span>
      </td>
      <td>
        <span style="background: ButtonFace; color: ButtonText; border: 
        medium outset ButtonShadow; 
        width: 5em; display: block; font-weight: bold; text-align: center;">
        OK</span>
      </td>
      <td>
        <span style="background: ButtonFace; color: ButtonText; border: 
        medium outset ButtonShadow; 
        width: 5em; display: block; font-weight: bold; text-align: center;">
        Preview</span>
      </td>
    </tr>
  </tbody>
</table>
            

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure

Find all references in the Web unit that mention the shape, size, or position of an object. For each such item:

  1. Check that the reference contains additional information that allows the item to be located and identified without any knowledge of its shape, size, or relative position.

Expected Results
  • Check #1 is true.


G97: Providing the abbreviation immediately following the expanded form

Applicability

Any technology containing text.

This technique is referenced from:

Description

The objective of this technique is to make the expanded form of an abbreviation available by associating the expanded form with its abbreviation the first time it occurs within an authored component. The expansion of any abbreviation can be found by searching the current authored component for the first use.

When shortening a word, phrase or name by means of an abbreviation, initialism, acronym, or other shortened form, provide the full form before providing the abbreviated form. This makes the text easier to read and is advised by many style guides.

Note that some abbreviations require explanations rather than expansions. This technique is not appropriate for such abbreviations.

This technique is applied to the first occurrence of an abbreviation in each authored component. When composing authored components into a single Web unit, the abbreviation would be expanded at the beginning of each component. A different technique for providing the expanded form may be more appropriate in this situation.

Examples

Example 1

"The United Nations High Commissioner for Human Rights (UNHCR) was established in 1950 to provide protection and assistance to refugees."

Resources

(none currently listed)

Tests

Procedure

For each abbreviation in the content,

  1. Search for the first use of that abbreviation in the authored component.

  2. Check that the first use is immediately preceded by the expanded form of the abbreviation.

  3. Check that the expanded form is the correct expanded form for the use of the abbreviation.

Expected Results
  • Checks #2 and #3 are true.


G98: Providing the ability for the user to review and correct answers before submitting

Applicability

Sites that collect data from users that is specific to the moment it is submitted, such as test data, and cannot be changed once it is submitted.

This technique is referenced from:

Description

The objective of this technique is to provide users with a way to ensure their input is correct before completing an irreversible transaction. Testing, financial, and legal applications permit transactions to occur which cannot be "undone". It is therefore important that there be no errors in the data submission, as the user will not have the opportunity to correct the error once the transaction has been committed.

On a simple, 1-page form this is easy because the user can review the form before submitting. On a form that spans multiple Web units, however, data is collected from the user in multiple steps before the transaction is committed. The user may not recall all of the data that was entered in previous steps before the step which commits the transaction.

One approach is to cache the results of each individual step and allow the user to navigate back and forth at will to review all data entered. Another approach is to provide a summary of all data collected in all steps for the user to review prior to the final commitment of the transaction.

Before the final step that commits the transaction to occur, instructions are provided to prompt the user to review the data entered and confirm. Once the user confirms, the transaction is completed.

Examples

  • An online banking application provides multiple steps to complete a transfer of funds between accounts as follows:

    1. Select "transfer from" account

    2. Select "transfer to" account

    3. Enter transfer amount

  • A summary of the transaction is provided showing the from and to accounts and the transfer amount. The user can select a button to either complete the transaction or cancel it.

  • A testing application provides multiple pages of questions. At any time, the user can choose to return to previously completed sections to review and change answers. A final page is displayed providing buttons to either submit the test answers or review answers.

Tests

Procedure

In a testing application or one that causes financial or legal transactions to occur and that also collects data from users in multiple steps:

  1. Determine if the user is allowed to return to previous steps to review and change data.

  2. Determine if a summary of all data input by the user is provided before the transaction is committed and a method is provided to correct errors if necessary.

Expected Results
  • Either #1 or #2 is true.


G99: Providing the ability to recover deleted information

Applicability

Content where user actions cause content to be deleted.

This technique is referenced from:

Description

When a Web application provides the capability of deleting information, the server can provide a means to recover information that was deleted in error by a user. One approach is to delay deleting the data by merely marking it for deletion or moving it to a holding area (such as a trash can) and waiting some period of time before actually deleting it. During this time period, the user can request that the data be restored or can retrieve it from the holding area. Another approach is to record all delete transactions in such a way that data can be restored if requested by the user, such as in the edit history stored by wikis and source control applications.

Examples

  • A Web application allows users to set up folders and store data within them. Each folder and data item is accompanied by a checkbox to mark it for action, and two buttons, one to move and one to delete. If the user selects the delete button by mistake, large amounts of data could be lost. The application presents the data as deleted to the user right away, but schedules it for actual deletion in one week. During the week, the user may go into a "deleted items" folder and request any folder or data item awaiting actual deletion to be restored.

Tests

Procedure
  1. Identify functionality that allows deleting content

  2. Delete content and attempt to recover it.

  3. Check if deleted information can be recovered.

Expected Results
  • #3 is true.


G100: Providing the accepted name or a descriptive name of the non-text content

Applicability

All technologies

This technique is referenced from:

Description

The objective of this technique is to allow users to identify the non-text content even if the non text content is intended to provide a specific sensory experience. For example, a deaf person may want to know what an audio instrumental file is - even if they cannot hear it. Similarly, a blind person may want to know what the subject of a visual image is - even if they cannot see it.

Examples

Example 1
  • Example 1: A painting of the Mona Lisa has an alternate text of "Mona Lisa, by Leonardo da Vinci"

  • Example 2: A sound file has an alternate text of "5 Grade schoolers playing a Theramin".

  • Example 3: A famous modern art piece is labeled "Red, Blue and Yellow, by Piet Mondrian"

Resources

(none currently listed)

Tests

Procedure
  1. Check that alternate text provides a descriptive name

  2. Check that alternate text provides a name that has be previously given to the non-text content by the author or another.

Expected Results
  • #1 or #2 is true


G101: Providing the definition of a word or phrase used in an unusual or restricted way

Applicability

Any technology containing text.

This technique is referenced from:

Description

The objective of this technique is to provide a definition for any word used in an unusual or restricted way.

A word is used in an unusual or restricted way when:

  • dictionaries give several definitions of the word but one specific definition must be used in order to understand the content;

  • a specific definition must be used in order to understand the content and dictionaries list that definition as rare, archaic, obsolete, etc.;

  • the author creates a new definition that must be used in order to understand the content.

This technique can also be used to provide definitions for jargon, that is, the specialized vocabulary used in a particular profession or technical field and understood by people in that field but not by people outside the field.

The technique can also be used to define idiomatic expressions. For example, speakers of a language who live in a particular region may use idiomatic expressions that are accepted by everyone in the region but not by people from other regions where the same language is spoken.

Examples

Example 1: A term used in a restricted way

The word "technology" is widely used to cover everything from the stone tools used by early humans to contemporary digital devices such as cell phones. But in WCAG 2.0, the word technology is used in a more restricted way: it means markup languages, programming languages, data formats, style sheets, and Application Programming Interfaces (APIs) used in producing and delivering Web content.

Example 2: A word used according to an obsolete definition

The word "ether" is defined as a substance that filled interplanetary space: "He believed that sound traveled through the ether."

Example 3: Jargon

The word "driver" is defined as software that contains specific instructions for a printer: "It may be necessary to update the driver for your printer."

Example 4: An idiomatic expression

Some people say "kicked the bucket" when they mean "died", e.g., "No one was surprised when the old fellow finally kicked the bucket."

Example 5: An idiomatic expression in Japanese

This example uses parentheses to provide the definition of an idiomatic expression in Japanese. The phrase in Japanese says that "he threw a spoon." It means that there was nothing he could do and finally he gave up.

さじを投げる(どうすることもできなくなり、あきらめること)。

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure

For each word or phrase used in an unusual or restricted way:

  1. Check that a definition is provided for the word or phrase

Expected Results
  • Check #1 is true.


G102: Providing the expansion or explanation of an abbreviation

Applicability

Any technology containing text.

This technique is referenced from:

Description

The objective of this technique is to provide information necessary to understand an abbreviation.

An abbreviation is the shortened form of a word, phrase, or name. For most abbreviations, providing the full word, phrase, or name is sufficient.

Some abbreviations represent words or phrases that are borrowed from a foreign language. For instance, many commonly used abbreviations in English are derived from Latin phrases, such as the short list of examples given below. The expanded form is only provided here as background information. For this category of abbreviations, providing an explanation is more helpful than the original expanded form, and the explanation of the abbreviation is provided instead of the expansion.

Abbreviation Latin expansion Explanation
a.m. ante meridiem before noon; in the morning
p.m. post meridiem after noon; in the afternoon
e.g. exempli gratia for example
cf confer/conferatur compare

If acronyms do not need an expansion (for example, because the original expansion has been rejected by the organization that it refers to or if the abbreviation has become part of the language), provide an explanation, if appropriate, or treat the abbreviation as a word that does not require explanation.

Examples

Example 1: ADA

Some abbreviations have more than one meaning, and the meaning depends on the context. For example, ADA means "American Dental Association" in one context and "Americans with Disabilities Act" in another. Only the expansion relevant to the context needs to be provided.

Example 2: English abbreviations for phrases borrowed from Latin

In the following sentence, the explanation "for example" would be provided for "e.g.": Students participating in team sports, e.g. basketball or football, must set their schedules around team practice time.

Example 3: ABS

Some languages (including English and Dutch) borrowed the acronym ABS (Antiblockiersystem: anti-lock brakes) from German. An explanation (anti-lock brakes) is provided, rather than the expansion

Example 4: acronyms with no expansion

Examples of acronyms which no longer have expansions include

  • SIL, which used to mean Summer Institute of Linguistics, is now a name in its own right. See SIL history.

  • IMS, which used to mean Instructional Management Systems, is now a name in its own right.

For this category of examples, a short explanation of what the organization is or does is sufficient.

Example 5: Abbreviations that have become part of the language

The Dutch fragment "'s nachts" meaning "at night" was originally an abbreviation for "des nachts". In the current Dutch language, the word "des" is rarely used anymore and perceived as archaic. Providing an expansion could be confusing. For "'s nachts" an expansion is not provided.

The English phrase "o'clock" was originally an abbreviation for "of the clock". Since then, "o'clock" has become part of the English language and an expansion does not need to be provided.

Resources

(none currently listed)

Tests

Procedure

For each abbreviation in the content,

  1. If the abbreviation has no expanded form, an explanation is provided.

  2. If the expanded form of the abbreviation is in a different language than the content, an explanation is provided.

  3. Otherwise, the expanded form is provided.

Expected Results
  • All the checks above are true.


G103: Providing visual illustrations of complex ideas, events, and processes

Applicability

All technologies.

This technique is referenced from:

Description

The objective of this technique is to provide visual illustrations that help users with reading disabilities understand difficult text that describes concepts or processes. The illustrations are provided in addition to the text.

Users with disabilities that make it difficult to decode words and sentences are likely to have trouble reading and understanding complex text. Charts, diagrams, animations, photographs, graphic organizers, or other visual materials often help these users. For example:

  • Charts and graphs help users understand complex data.

  • Diagrams, flowcharts, videos, and animations help users understand processes.

  • Concept maps and other graphic organizers help users understand how ideas are related to each other.

  • Photographs, drawings, and videos can help users understand natural or historical events or objects.

Examples

Example 1: An annual report for a company

An annual report discusses multiple factors that influenced the company’s performance in the past year. The report also includes charts and graphs that illustrate how these factors interact. Each chart or graph has a text alternative as required by Success Criterion 1.1.1. Each one also has a number in its caption (e.g., “Figure 7”). These numbers are used in the text to reference the charts or graphs.

Example 2: Screen shots in technical documentation

Online documentation for a product includes step by step instructions. Each step is illustrated by a screen shot that shows the visual appearance of the screen. Each screen shot has text alternatives as required by Success Criterion 1.1.1.

Example 3: Illustrations of a complex natural event

A Web site discusses the tsunami of 2004. The site describes how the tsunami affected different places around the Indian Ocean. Photographs of the devastation in each area are included. Each photograph has a text alternative as required by Success Criterion 1.1.1. The site also explains what happens underwater during a tsunami. The explanation is accompanied by an animation that shows how a tsunami occurs and spreads over the ocean. The animation has a text alternative as required by Success Criterion 1.1.1.

Resources

  • Hall, T., and Strangman, N. CAST: Graphic organizers. Retrieved 5 April 2005 from NCAC Publications. This article illustrates several different kinds of graphic organizers, explains how each type may be useful, and summarizes research findings that graphic organizers support learning, especially among students with learning disabilities.

  • Tufte, Edward. Envisioning information. Cheshire, Conn.: Graphics Press. 1990.

  • Tufte, Edward. The visual display of quantitative information. Cheshire, Conn.: Graphics Press. 1983.

  • Tufte, Edward. Visual explanations : images and quantities, evidence and narrative. Cheshire, Conn.: 1997.

(none currently listed)

Tests

Procedure
  1. Identify text that discusses ideas or processes that must be understood in order to use the content.

  2. Check if visual illustrations are available in the content or through links within the content.

  3. Check that visual illustrations show the concepts or processes discussed in the text.

Expected Results
  • Checks #2 and #3 are true.


G104: Satisfying all WCAG success criteria at levels 1 and 2 that the technology outside the baseline can support

Applicability

All technologies that support conformance to any of the WCAG Level 1 and 2 requirements.

This technique is referenced from:

Description

The objective of this technique is to ensure that as many WCAG success criteria are met as possible, even for technologies that are outside the baseline and not subject to WCAG conformance requirements. Often, technologies that are outside the baseline will not have a solid set of techniques that enable conformance with all WCAG Level 1 and 2 requirements; this may be a major reason the technology is outside the baseline. Authors can still implement as many of the general techniques as possible and all of the techniques that are known to be available for the technology in order to conform with as many WCAG Level 1 and 2 success criteria as possible.

Examples

Example 1

A Web site uses a technology that is outside the baseline to present some content. An alternative version is provided that conforms to WCAG at the targeted level. However, the version that is in the non-baseline technology does conform to as many WCAG Level 1 and 2 requirements as possible. Here are some examples of things that do conform:

  • All pictures that convey information are described (1.1)

  • There are no time-outs, forms, or multimedia or flashing content at all (1.2, 2.2, 2.3, 2.5)

  • Color is used only to enhance the content but is not used to convey information that would be lost if the user could not discern the color differences (1.3)

  • Text and background colors provide sufficient contrast (1.4)

  • All interaction is keyboard operable and users can exit the content using the keyboard. (2.1)

  • Navigation mechanisms are consistently implemented and no changes of context occur as a result of changing focus to a control or changing the setting of a control (3.2)

But the technology does not provide a way a means to meet all of the WCAG Level 1 and 2 success criteria.The technology does not support programmatically communicating structures, natural languages, or role and state information. Therefore, the following things cannot be communicated to assistive technologies:

  • complex structures such as tables for perception (1.3) or navigation (2.4).

  • the primary language of the content or phrases or passages that are in another language (3.1).

  • the role and state of interactive controls (4.2)

Resources

(none currently listed)

Tests

Procedure

For all content that is implemented in a technology that is not in the baseline.

  1. Perform an assessment of the content against all WCAG Level 1 and 2 success criteria.

  2. For any failing conditions, determine if it is possible to meet the success criterion using the technology.

Expected Results

If #2 is false, the content passes this success criterion.


G105: Saving data so that it can be used after a user re-authenticates

Applicability

Web units that require user authentication and limit the time available for submitting data.

This technique is referenced from:

Description

Web servers that require user authentication often terminate the session after a set period of time if there is no activity from the user. If the user is unable to input the data quickly enough and the session times out before they submit, the server will require re-authentication before proceeding. When this happens, the server stores the data in a temporary cache while the user logs in, and when the user has re-authenticated, the data is made available from the cache and the form is processed as if there had never been a session time-out. The server does not keep the cache indefinitely, merely long enough to ensure success after re-authentication in a single user session, such as one day.

Examples

  • A user has logged in to use a forum and replies to a post. The time taken to write the reply is longer than the time allowed by the server for a session of inactivity. The user submits the reply and is informed of the time out and prompted to log in again to submit the response. The user's post reply is retained by the server and if the user log-in is successful the reply is processed as normal. If the log-in can not be successfully completed the reply is discarded.

  • The user had logged in to a secure area and fills out a form. The session times out for security reasons. The form data is retained by the server and the user is informed of the time out and is prompted to log-in again. If the user logs in correctly, the form is presented to the user with all of the data previously entered and user can submit the form. If the log-in can not be successfully completed the form data is discarded.

Tests

Procedure

On a site that requires user login to submit data,

  1. Log in and begin the timed activity.

  2. Allow the session to time out.

  3. Submit the data.

  4. Re-authenticate.

  5. Check that the process can continue and be completed without loss of data, including the original data and any changes made after re-authentication.

Expected Results
  • #4 is true.


G107: Using "activate" rather than "focus" as a trigger for changes of context

Applicability

Applies to all technologies.

This technique is referenced from:

Description

The objective of this technique is to provide a method for activating things that is predictable by the user. Users with cognitive disabilities and people using screen readers or screen magnifiers may be confused by an unexpected event such as automatic form submission or activation of a function that causes a change of context.

With this technique, all changes of context would be triggered only by a specific action on the part of the user. Further, that action would be one that usually causes changes in context, such as clicking on a link or pressing a submit button. Actions that simply move the focus to an element would not cause a change of context.

Examples

Example 1
  • A page pops up a new window only when the user clicks(or uses spacebar) on a button rather than using onfocus to pop up a new window.

  • A submit button is used to move on to the next data entry screen rather than having the next screen appear automatically when the user tabbed onto a 'done' button.

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure
  1. Using a keyboard, cycle focus through all content

  2. Check that no changes of context occur when any component receives focus.

Expected Results
  • #2 is true


G108: Using markup features to expose the name and role, allow user-settable properties to be directly set, and provide notification of changes

Applicability

Markup technologies where it is possible to expose the name and role, allow user-settable properties to be directly set, and provide notification of changes.

This technique is referenced from:

Description

The objective of this technique is to allow assistive technology to understand Web content so that it can convey equivalent information to the user through an alternate user interface and allow them to operate controls through the AT.

This technique involves using standard, documented and supported features to expose these properties to AT. It relies on the fact that these standard controls in standard browsers meet the requirements.

For HTML these assumptions are good. They may also be appropriate for some other technologies.

Even when the components support accessibility, it is essential that some information be provided by the author. For example, a control may have the ability to provide a name but the author still has to provide the name. The role attribute however may already be provided since it is a standard component with a fixed role.

Examples

Example 1

Example 1: A Web page written in HTML or XHTML uses standard form controls, and identifies the form control using the title attribute. The user agent makes information about these controls, including the name, available to assistive technology through the DOM and through a platform-specific Accessibility API.

Resources

(none currently listed)

Tests

Procedure
  1. Visually inspect the markup or use a tool.

  2. Check that proper markup is used such that the name and role, for each user interface component can be determined.

  3. Check that proper markup is used such that the user interface components that accept user input can all be operated from AT.

Expected Results
  • Step #2 and #3 are both true for each user interface component


G110: Using an instant client-side redirect

Applicability

Applies to all technologies.

This technique is referenced from:

Description

The objective of this technique is to enable redirects on the client side without confusing the user. Redirects are preferably implemented on the server side (see Implementing automatic redirects on the server side instead of on the client side), because a server-side redirect does not cause new content to be displayed before the server sends the content located at the new URL. However, authors do not always have control over server-side technologies; in that case, they can use a client-side redirect. A client-side redirect is implemented by code inside the content that instructs the user agent to retrieve content from a different URL. It is important that the redirecting page or Web unit only contains information related to the redirect.

Examples

Example 1: HTML: meta Refresh With a URL and No Timeout

In HTML 4.x and XHTML 1.x, it is possible to implement a client-side redirect using the meta element: see Using meta refresh to create an instant client-side redirect.

Resources

Tests

Procedure
  1. Find each link or programmatic reference to another page or Web unit.

  2. For each link or programmatic reference, check if the referenced Web unit contains code (e.g. meta element or script) that causes a client-side redirect.

  3. For each link or programmatic reference that causes a client-side redirect, check if the redirect is implemented without a time-out or delay and that the page only contains information related to the redirect.

Expected Results

Step 2 is false or step 3 is true.


G111: Using color and pattern

Applicability

All technologies that support images.

This technique is referenced from:

Description

The objective of this technique is to ensure that when color is used within an image to convey information, patterns are included to convey the same information in a manner that does not depend on color.

Examples

Example 1

A real estate site provides a bar chart of average housing prices in several regions of the United States. The bar for each region is displayed with a different solid color and a different pattern. There is sufficient contrast between the solid and pattern colors to meet Success Criterion 1.4.1. The legend uses the same colors and patterns to identify each bar.

Example 2

An on-line map of a transportation system displays each route in a different color. The stops on each route are marked with a distinctive icon such as a diamond, square, or circle to help differentiate each route.

Example 3

A flow chart describes a set of iterative steps to complete a process. It uses dashed, arrowed lines with a green background to point to the next step in the process when the specified condition passes. It uses dotted arrowed lines with a red background to point to the next step in the process when the specified condition fails. There is sufficient contrast between the line and background colors to meet success criterion 1.4.1.

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure

For each image within the Web unit that use color to convey information:

  1. Check that all information that is conveyed using color is also conveyed using patterns that do not rely on color.

Expected Results
  • Check #1 is true.


G112: Using inline definitions

Applicability

Any technology containing text.

This technique is referenced from:

Description

The objective of this technique is to provide a definition in context for any word used in an unusual or restricted way. The definition is provided in the text, either just before or just after the word is used. The definition may be included in the same sentence as the word that is being defined, or in a separate sentence.

Examples

Example 1: Ether

He believed that sound traveled through the ether, which was thought to be a substance that filled interplanetary space.

Example 2: Driver

It may be necessary to update the driver for your printer (the driver is software that contains specific instructions for your printer).

Example 3: W3C key words

Definition: The key words must, must not, required, shall, shall not, should, should not, recommended, may, and optional in this specification are to be interpreted as described in RFC 2119.

Example 4: A Japanese idiomatic expression defined in context

This example uses parentheses to provide the definition of an idiomatic expression in Japanese. The phrase in Japanese says that "he threw a spoon." It means that there was nothing he could do and finally he gave up.

さじを投げる(どうすることもできなくなり、あきらめること)。

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure

For each word or phrase used in an unusual or restricted way:

  1. Check that the word is defined in text either before or after the first occurrence of the word.

Expected Results
  • Check #1 is true.


G115: Using semantic elements to mark up structure

Applicability

Markup languages, including HTML 4.01, XHTML 1.x

This technique is referenced from:

Description

The objective of this technique is to mark up the structure of the Web content using the appropriate semantic elements. In other words, the elements are used according to their meaning, not because of the way they appear visually.

Using the appropriate semantic elements will make sure the structure is available to the user agent. This involves explicitly indicating the role that different units have in understanding the meaning of the content. The nature of a piece of content as a paragraph, header, emphasized text, table, etc. can all be indicated in this way. In some cases, the relationships between units of content should also be indicated, such as between headings and subheadings, or amongst the cells of a table. The user agent can then make the structure perceivable to the user, for example using a different visual presentation for different types of structures or by using a different voice or pitch in an auditory presentation.

In HTML, for example, phrase-level elements such as em, abbr, and cite add semantic information within sentences, marking text for emphasis and identifying abbreviations and citations, respectively. MathML, a markup language designed to maintain important distinctions between structure and presentation in mathematics, includes special "presentation" markup for the complex notations used to represent mathematical ideas as well as "content" (semantic) markup for the mathematical ideas themselves.

Examples

Example 1

A paragraph contains a hyperlink to another page. The hyperlink is marked up using the a element.

<p>Do you want to try our new tool yourself? A free 
demonstration version is available in our 
<a href="download.html">download section</a></p>
Example 2

A page about the history of marriage uses a quotation from Jane Austen's novel, Pride and Prejudice, as an example. The reference to the book is marked up using the cite element and the quotation itself is marked up using the blockquote element.

<p>Marriage was considered a logical step for a bachelor, 
as can be seen in the first chapter of the novel 
<cite>Pride and Prejudice</cite>:</p>
<blockquote>
     <p>It is a truth universally acknowledged, that a single man in
     possession of a good fortune, must be in want of a wife.</p>

     <p>However little known the feelings or views of such a man may
     be on his first entering a neighbourhood, this truth is so well
     fixed in the minds of the surrounding families, that he is considered
     the rightful property of some one or other of their daughters.</p>
</blockquote>
Example 3

A car manual explains how to start the engine. The instructions include a warning to make sure the gear is in neutral. The author feels the warning is so important that it should be emphasized so the warning is marked up using the strong element.

<h1>How to start the engine</h1>
<p>Before starting the engine, <strong>make sure the gear 
is in neutral</strong>. Next, turn the key in the ignition. 
The engine should start.</p>
Example 4

This example shows how to use the em and strong elements to emphasize text.

<p>What she <em>really</em> meant to say was, 
"This is not ok, it is <strong>excellent</strong>!"</p>

Resources

Tests

Procedure
  1. Check if there are parts of the content that have a semantic function.

  2. For each part that has a semantic function, if corresponding semantic markup exists in the technology, check that the content has been marked up using that semantic markup.

Expected Results
  • Check #2 is true.


G117: Using text to convey information that is conveyed by variations in presentation of text

Applicability

Technologies that support variations in the visual presentation of text.

This technique is referenced from:

Description

The objective of this technique is to ensure that information conveyed through variations in the formatting of text is conveyed in text as well. When the visual appearance of text is varied to convey information, state the information explicitly in the text. Variations in the visual appearance can be made by changes in font face, font size, underline, strike through and various other text attributes. When these types of variations convey information, that information needs to be available elsewhere in the content via text. Including additional sections in the document or an inline description where the variation in presentation of text occurs can be used to convey the information.

Examples

Example 1: An on-line test requires students to write a short summary of a longer document.

When a sentence in the original document contains a word or phrase that must be used in the summary, the word or phrase is shown in a different font than the rest of the sentence. A separate section also lists all the words and phrases that must be used in the summary.

Example 2: Font variations and explicit statements.

An on-line document has gone through multiple drafts. Insertions are underlined and deletions are struck through. At the end of the draft a "change history" lists all changes made to each draft.

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure
  1. Find items where variations in presentation of text are used to convey information.

  2. For those items, check to determine if information conveyed visually is also stated explicitly in text.

Expected Results
  • Check #2 is true.


G120: Providing the pronunciation immediately following the word

Applicability

All technologies.

This technique is referenced from:

Description

The objective of this technique is to make the pronunciation of a word available by providing the pronunciation after the word at least the first time it occurs within an authored component.

When an authored component contains words with the same spelling but different pronunciations, this technique is not appropriate for providing the pronunciation unless it is provided for each instance.

When this technique is applied to the first occurrence of a word in each authored component and when authored components are combined into a single Web unit, the word's pronunciation would be provided at the beginning of each component. A different technique for providing the pronunciation may be more appropriate in this situation.

Examples

Example 1

In the following example of Japanese text, the information giving the pronunciation in Han characters(Kanji) is rendered in parentheses immediately following the text.

<p> 慶應大学 (けいおうだいがく) </p>

Resources

No resources available for this technique.

Tests

Procedure

For each word that requires pronunciation information:

  1. Search for the first use of that word in the authored component.

  2. Check that the first use is immediately followed by the pronunciation of the word.

Expected Results
  • Check #2 is true.


G121: Linking to pronunciations

Applicability

All technologies that include links.

This technique is referenced from:

Description

The objective of this technique is to make the pronunciation of a word available by providing information about the pronunciation, either within the same Web unit or in a different Web unit, and establishing a link between the item and its pronunciation.

Examples

Example 1

A word is linked to its entry in a dictionary that includes pronunciation information.

Example 2

A word is linked to a sound file that will speak the pronunciation.

Example 3

A word in linked to its entry in a pronouncing dictionary.

Example 4

A word is linked to an International Phonetic Alphabet (IPA) representation of its pronunciation.

Example 5

A word is linked to an unambiguous phonetic spelling of the pronunciation.

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure

For each word that requires pronunciation information:

  1. Check that at least the first instance of the item is a link.

  2. Check that each link navigates to information about the pronunciation of the item.

Expected Results
  • All checks are true.


G122: Including a text cue whenever color cues are used

Applicability

All technologies that support color and text.

This technique is referenced from:

Description

The objective of this technique is to combine color and text or character cues to convey information. Most users can quickly scan the content to locate information conveyed by using color. Users who cannot see color can look or listen for text cues; people using Braille displays or other tactile interfaces can detect text cues by touch.

Examples

Example 1: Required fields in an HTML form

The instructions for an online form say, "Required fields are shown in red and marked with (req)." The cue "(req)" is included within the label element.

<label for="lastname" class="required">Last name(req):</label>
<input id="lastname" type="text" size="25" value=""/>
.required {
color=red;
}

Resources

No resources available for this technique.

Tests

Procedure

For any content where color is used to convey information:

  1. Check that the same information is available through text or character cues.

Expected Results
  • Check #1 is true.


G123: Adding a link at the beginning of a block of repeated content to go to the end of the block

Applicability

All technologies that contains links.

This technique is referenced from:

Description

The objective of this technique is to provide a mechanism to bypass blocks of material that are repeated on multiple Web units. The first link in the block or the link directly preceding the block is a link to the content immediately after the block. Activating the link advances the keyboard focus past the block.

Examples

Example 1: Skip navigation links

The pages on an organization's Web site include a navigation bar or main menu containing links to major sections of the site, the site map, information about the organization, and how to contact the organization. The first link in this area is titled "Skip Navigation Links". A user activates the link to skip over these links.

Example 2: A book index

A book contains an index that is divided into a set of pages. In the content at the beginning of each page of the index are links for each letter of the alphabet, linking into the index where the entries start with that letter. The first link in the set is titled "Skip Links into Index". A user activates this link to skip over the links.

Example 3: Several sets of links

All the pages on a Web site include a section containing links to the site map, information about the organization, and how to contact the organization. All the pages in each section of the site also contain a set of links to its subsections. The first link in the first block is titled "Skip Navigation Links" and skips over the first set of links. The first link in the second block is titled "Skip Section Links" and skips over the subsection links.

Resources

Tests

Procedure

  1. Check that a link is the last focusable control before the block of repeated content or the first link in the block.

  2. Check that the description of the link communicates that it skips the block.

  3. Check that activating the link moves the focus to the content immediately after the block.

  4. Check that after activating the link, the keyboard focus has moved to the content immediately after the block.

Expected Results
  • All checks above are true.


G124: Adding links at the top of the page to each area of the content

Applicability

All technology that contains links

This technique is referenced from:

Description

The objective of this technique is to provide a mechanism to bypass blocks of material that are repeated on multiple Web units by providing a small list of links to different sections of the content at the beginning of the content. Activating one of these links sets focus to that section of the content. The number of links in the list should be kept very small; otherwise, a mechanism may also be needed to skip them.

Examples

Example 1

The Web units on a site all start with three links that navigate to the main content of that Web unit, the search field, and the navigation bar.

Resources

Tests

Procedure

For each link in the set of links provided for this purpose:

  1. Check that the only controls in the Web unit that precede the link are other links in the set.

  2. Check that the description of each link communicates that it links to some section of the content.

  3. Check that activating the link moves the focus to that section of the content.

Expected Results
  • All checks above are true.


G125: Providing links to navigate to related Web units

Applicability

All technologies that contains links

This technique is referenced from:

Description

The objective of this technique is to make it possible for users to locate similar information by providing links to related Web units. Links are a basic component of the World Wide Web. They are the mechanism that makes the Web an interconnected Web of content. Most authors employ this technique automatically when creating Web units.

Examples

Example 1

The Web Content Accessibility Guidelines 2.0 contains links to definitions of terms used in guidelines and success criteria, links to documents explaining how to meet different success criteria, a table of contents for each section containing links to different subsections of that section, and links to related documents such as a About Baselines for WCAG 2.0, and a Comparison of WCAG 1.0 checkpoints to WCAG 2.0. As users browse the document, they can follow these links to find related information.

Resources

Tests

Procedure

For each link in the set of links provided for this purpose:

  1. Check whether a Web unit contains links

  2. For each link, check whether the link leads to related information.

Expected Results
  • Check #2 is true.


G126: Providing a list of links to all other Web units

Applicability

All technologies that contains links

This technique is referenced from:

Description

The objective of this technique is to provide a list of links to all the Web units of the site on each Web unit. This technique is only effective for small Web sites; if the list of links is longer than the rest of the content in the Web unit, it may make the Web unit more difficult for users to understand and use. Note that Success Criterion 2.4.1 requires a technique for skipping this list of links.

Examples

Example 1

A family Web site contains home pages for all the members of the family. Each page contains a list of links to the home pages of the other family members.

Example 2

An electonic book is broken into separate Web units for each chapter. Each Web unit starts with a small Table of Contents that contains links to all the chapters in the book.

Resources

No resources available for this technique.

Tests

Procedure
  1. Check that each Web unit contains a list of links to the other Web units in the site

  2. Check that the links in the list lead to the corresponding Web units.

  3. Check that the list contains a link for every Web unit in the site.

Expected Results
  • All of the checks above are true.


G127: Identifying a Web unit's relationship to a larger collection of Web units

Applicability

All technologies.

This technique is referenced from:

Description

The objective of this technique is to enable users to identify the relationship between the current Web unit and other Web units in the same collection (e.g., on the same Web site). In some cases this can be done programmatically—for example by using the rel attribute of the link element in HTML. In other cases the information is provided by including the relevant information in the title of the Web unit.

Examples

Example 1: The title of a Web unit includes the name of the sub-site

A large Web site includes tutorials and reference materials for numerous technologies. The title of each Web unit includes the name of the sub-site as well as the organization that produces the site.

Example 2: Including identifying information in metadata

A Web unit includes metadata that identifies it as the table of contents for a collection of documents. The metadata for each document in the collection identifies the document’s position in the collection and provides a reference to the table of contents.

Example 3: Chapters in an online textbook

An online textbook is divided into chapters. The title of each Web unit includes the number and title of the chapter as well as the title of the textbook.

Resources

No resources available for this technique.

Tests

Procedure
  1. Check if the title of the Web unit describes the Web unit’s relationship to the collection to which it belongs.

  2. Check if the Web unit includes metadata identifying the Web unit’s relationship to the collection to which it belongs.

Expected Results
  • Check #1 or check #2 is true.


G128: Indicating current location within navigation bars

Applicability

All technologies.

This technique is referenced from:

Description

The objective of this technique is to help orient the user within a set of Web units by providing information about the current location via the navigational user interface component. Providing this indication helps the user to better understand his place in the collection of Web units. The location may be indicated by adding an icon or text, or by changing the state of the item.

Examples

Example 1

A Web unit implements tab panel style navigation. A list of panel tabs is displayed horizontally across the page. The current content is displayed in a panel below the list of panel tabs. When the user navigates to and selects a particular panel tab the content in the panel is updated to reflect the topic of the selected tab. In addition, the background color of the selected tab is changed from the default color and a check mark icon is displayed next to the tab panel text to indicate it is the active panel. The check mark icon includes an appropriate text alternative.

Example 2

The layout for a Web unit uses a frameset and frames. One of the frames is designated as the navigation frame and another frame displays the content of the Web site. When the user selects a link in the navigation frame, the information related to the link is displayed within the content frame. The text for the selected item in the navigation frame is updated with an asterisk character to indicate that it is the selected topic.

Example 3

The navigation bar for a site is implemented as a list of links. The navigation bar appears on all Web units within a collection of Web units. As the user gives focus to or hovers over a particular link in the navigation bar the background color of the link is changed. This change in styling on mouseover or focus is specified via the cascading style sheet for the Web unit. When focus is removed from the link the style is reset to the normal link style. When the link is activated to change the contents of the page, the selected link within the navigation bar is disabled since the result of following this link is the Web unit currently being displayed. Changing the background color gives sighted users visual notification of the link to be selected. Disabling the link provides information to all users that it is the currently selected topic.

Resources

No resources available for this technique.

Tests

Procedure

When the navigation component is repeated within a set of Web units :

  1. Check that the user is giving an indication of the currently selected item within the navigational unit.

  2. Check that the selected item matches the content which is being displayed.

Expected Results
  • Checks #1 and #2 are true.


G130: Providing descriptive headings

Applicability

All technologies.

This technique is referenced from:

Description

The objective of this technique is to make section headings within Web content descriptive. Descriptive headings and titles (see Providing descriptive titles for Web units) work together to give users an overview of the content and its organization. Descriptive headings identify sections of the content in relation both to the Web unit as a whole and to other sections of the same Web unit.

Descriptive headings help users find specific content and orient themselves within the Web unit.

Users may become disoriented when long documents contain multiple sections with headings that are the same or very similar. Therefore, headings should be distinct within the Web unit.

Authors may also want to consider putting the most important information at the beginning of each heading. This helps users “skim” the headings to locate the specific content they need, and is especially helpful when browsers or assistive technology allow navigation from heading to heading.

Examples

Example 1

An HTML page that describes the range of tasks for disaster preparation may have the following headings:

  <h1>Disaster preparation</h1>
  <h2>Flood preparation</h2>
  <h2>Fire preparation</h2>

Note that the level 2 headings have the distinguishing information at the beginning (ie, instead of "Preparation for floods", "Preparation for fires", etc).

Example 2

A short article about the history of a town that explains about the founding and expansion of the town and then goes into some depth about the current situation. The title of the Web unit is "History of Ourtown". The first section is called "The founding of Ourtown". The second section is called "Expansion of Ourtown". The third section is called "Ourtown today" which has the following subsections: "People in Ourtown", "Organizations in Ourtown" and "Buildings in Ourtown".

Resources

No resources available for this technique.

Tests

Procedure
  1. Determine if the Web unit contains headings.

  2. Check that each heading identifies its section of the content.

Expected Results
  • Check #2 is true.


G131: Providing descriptive labels

Applicability

All technologies.

This technique is referenced from:

Description

The objective of this technique is to ensure that the label for any interactive component within Web content makes the component’s purpose clear. Using the appropriate technology-specific techniques for technologies within your baseline allows assistive technology to recognize the label and present it to the user.

Examples

Example 1: Online maps with controls for zooming in and out

A Web application presents maps of a city. Users can “zoom in” to view part of the map in greater detail, and can “zoom out” to make the show a larger part of the city. The controls can be operated using either a mouse or a keyboard. The controls are labeled “Zoom in (Ctrl + Shift + L)” And “Zoom out (Ctrl + Shift + R).”

Example 2: A form asking the name of the user

A form asks the name of the user. It consists of two input fields to ask for the first and last name. The first field is labeled "First name", the second is labeled "Last name".

Example 3: A form with required fields

A purchasing form includes several fields that are required. In addition to identifying the field, the label for each required field includes the word “required” in parentheses.

Resources

No resources available for this technique.

Tests

Procedure

For each interface component in the content:

  1. Identify the purpose of the interface component.

  2. Check that any required label is present.

  3. Check that each label makes the component’s purpose clear.

Expected Results
  • Checks #2 and #3 are true.


G133: Providing a checkbox on the first page of a multipart form that allows users to ask for longer session time-out or no session time-out

Applicability

Content that includes multipart forms

This technique is referenced from:

Description

The objective of this technique is to minimize the risk that users with disabilities will lose their work by providing a checkbox to request additional time to complete multipart forms. The checkbox can allow the user to request a specific amount of additional time (for example 15 minutes) or an indefinite extension. (Note that allowing an indefinite extension would be inappropriate if it jeopardized user privacy or network security.)

Examples

Example 1: A checkbox for requesting a specific extension

A Web unit contains the first part of a five-part form. Immediately following the general instructions for completing the form is a checkbox with the label, “Allow an additional 15 minutes to complete each part of this form.”

Example 2: Requesting an indefinite extension

A Web unit contains the first part of a three-part form. Each part of the form includes more than 10 items. Some items require users to follow links for additional information. Immediately following the general instructions for completing the form is a checkbox with the label, “Allow as much time as I need to complete this form. I understand that I must close (quit) the Web browser if I choose to stop before completing the last part of the form.”

Tests

Procedure

If the Web unit contains the first part of a multipart form:

  1. Check that the Web unit includes a checkbox to request additional time to complete the form.

  2. Check that if the checkbox is checked, additional time is provided to complete the form.

Expected Results
  1. All checks are true.


G134: Validating Web units

Applicability

Any markup languages and many other technologies.

This technique is referenced from:

Description

The objective of this technique is to avoid ambiguities in Web units that often result from code that does not validate against formal specifications. Each technology's mechanism to specify the technology and technology version is used, and the Web unit is validated against the formal specification of that technology. If a validator for that technology is available, the developer can use it.

Validation will usually eliminate ambiguities (and more) because an essential step in validation is to check for proper use of that technology's markup (in a markup language) or code (in other technologies). Validation does not necessarily check for full conformance with a specification but it is the best means for automatically checking content against its specification.

Examples

Example 1: Validating HTML

HTML pages include a document type declaration (sometimes referred to as !DOCTYPE statement) and are valid according to the HTML version specified by the document type declaration. The developer can use off-line or online validators (see Resources below) to check the validity of the HTML pages.

Example 2: Validating XML

XHTML, SVG, SMIL and other XML-based documents reference a Document Type Definition (DTD) or other type of XML schema. The developer can uses online or off-line validators (including validation tools built into editors) to check the validity of the XML documents.

Example 3: Batch validation with Ant

The xmlvalidate task of Apache Ant can be used for batch validation of XML files. The following Apache Ant target is a simple example for the validation of files with the extension .xml in the directory dev\\web (relative to the Ant build file).

   <target name="validate-xml"> 
   <xmlvalidate lenient="no"> 
   <fileset dir="dev\\web" includes="*.xml" /> 
   </xmlvalidate> 
   </target>  

Resources

Validating HTML and XHTML

Validating XML

  • HTML/XHTML/WML/XML Validator allows you to validate documents by URL or by file upload. An extended interface is also available.

  • HTML/XHTML/WML/XML Validator is a German version of the same validator.

  • XML Validator - A Document Validation Service by JavaView allows you to check wellformedness and validity of XML files, by file upload or by direct input of XML code.

  • Apache Ant's XMLValidate Task can be used to validate XML-based documents. This tool can be used to validate entire directories (and subdirectories) of XML files.

  • The Sun Multi-Schema XML Validator is a command-line validator in Java that supports validation against a range of schema languages including DTDs, RELAX NG and TREX. Source code is available.

  • XML Schema Validator by Christoph Schneegans is an online tool that allows you to validate XML (and XHTML) files by by URL, by file upload, by direct input of complete XML documents, and by direct input of XML code fragments. A bookmarklet that allows you to validate the page currently displayed in your browser is also available. This validator claims to be more accurate than the W3C validator.

  • XML Schema Validator by DecisionSoft is an online tool that allows you to validate an XML file against a W3C XML Schema, both of which can be uploaded.

  • XSD Schema Validator by GotDotNet is an online tool that allows you to validate an XML file against a W3C XML Schema or an XML Data-Reduced (XDR) schema, both of which can be uploaded.

  • STG XML Validation Form by the Scholarly Technology Group of Brown University allows you to validate XML files by URL, by file upload and by direct input of complete XML documents.

  • NetBeans: Working with XML, Part 1 and NetBeans: Working with XML, Part 2 by Tim Boudreau and others, explains how to enable XML support, validation and other related functionality in the open-source NetBeans framework. This article is also available as a single file: Working with XML .

Note that many programming editors, XML editors and integrated development environments (IDEs) can validate XML files. These include the following free and/or open-source tools:

  • the programming editor JEdit with the XML and SideKick plugins, which supports DTDs and W3C XML Schemas,

  • the “workbench” Eclipse with the Web Tools Platform ,

  • the Web authoring tool SCREEM for the Gnome desktop environment, which supports DTDs,

  • the XML editor Jaxe , which validates XML files with Apache Xerces,

  • the XML editor Xerlin , which supports DTDs and to some extent W3C XML schema,

  • the XML editor xmloperator , which supports DTDs and RELAX NG schemas,

  • Emacs in nXML mode (see the YahooGroup Emacs nXML Mode ),

  • the XML editor Pollo , which supports DTDs, W3C XML Schemas and RELAX NG schemas, and is best suited for tree-like XML files.

Validating CSS

  • The W3C CSS Validation Service allows you to validate CSS files by URL, by file upload and by direct input of CSS code.

  • The W3C CSS Validation Service: Validate by URI is an extended interface that allows you to specify a CSS stylesheet or an HTML page with CSS, specify the CSS profile and medium, and choose the types of warnings that should be displayed.

  • CSSCheck by the Web Design Group allows you to validate CSS files by URL and by direct input of CSS code. Note that it is primarily a CSS 1 checker.

  • CSSCheckUp by the Web Design Group allows you to validate CSS files by file upload. Note that it is primarily a CSS 1 checker.

  • CSS (Cascading Style Sheets) Validator allows you to validate CSS files by URL.

(none currently listed)

Tests

Procedure

For HTML, SGML-based and XML-based technologies:

  1. Load each page or document into a validating parser.

  2. Check that no validation errors are found.

For CSS:

  1. Load each external or internal stylesheet into a CSS validator.

  2. Check that no validation errors are found.

For other technologies:

Follow the validation procedure defined for the technology in use, if any exists.

Expected Results

For HTML, SGML-based and XML-based technologies:

Step 2 is true.

For CSS:

Step 2 is true.


G135: Using the accessibility API features of a technology to expose names and roles, to allow user-settable properties to be directly set, and to provide notification of changes

Applicability

programming technologies that have standard components that are programmed to interface with accessibility APIs

This technique is referenced from:

Description

The objective of this technique is to allow assistive technology to understand Web content so that it can convey equivalent information to the user through an alternate user interface.

Sometimes content is not created using markup language but rather using a programming language or tools. In many cases, these technologies have interface components that are already programmed to interface with accessibility APIs. If an author uses these components and fills in the properties (e.g. name, etc) the resulting user interface components in the content will be accessible to assistive technology.

Examples

Example 1
  • A Web unit uses java to create an applet. Java swing objects (e.g. pushbutton) are used because they have accessibility properties built in that can be accessed from assistive technology written in Java and, with the Java Access Bridge, those written in other languages that use the Accessibility API of the operating system. The author fills in the values for the components and the result is accessible to AT.

Resources

(none currently listed)

Tests

Procedure
  1. Render content using an accessible User Agent

  2. Use an Accessibility Tool designed for the Accessibility API of the User agent to evaluate each user interface component

  3. Check that name and role for each user interface component are found by the tool.

Expected Results
  • Step #3 is true for each user interface component


G136: Providing a link at the beginning of the nonconforming content that points to an alternate version that does meet WCAG 2.0 Level 1 success criteria

Applicability

Primary content does not conform to WCAG but alternate versions exist that do conform to WCAG. This technique can only be used if a technology makes it possible to create an accessible link to an alternate version.

This technique is referenced from:

Description

The objective of this technique is to enable users to access alternate content that does conform to WCAG if the primary content, or the default content that users access from a particular URI, does not conform. The alternate page may make some design or functionality compromises in order to conform but should provide the same content that is available in the primary content.

Placing a WCAG conforming link to alternate content at the top of the page allows users to find the link quickly and move to the alternate version. Each page needs a link to the WCAG conforming version of that page, to ensure users can always find it regardless of where they enter the site.

Examples

  • On a Web site, for each page that does not conform to WCAG at the declared level, the first link on the page is called "Alternate version". The target of this link is the alternative version of the page that conforms to WCAG at the declared level.

Tests

Procedure
  1. Identify a page that does not conform to WCAG at conformance Level 1.

  2. Determine if the page contains a link to an alternative version of the page.

  3. Determine if the alternative version conforms to WCAG at conformance Level 1.

Expected Results
  • Both #2 and #3 are true.


G137: Providing a link at the beginning of the nonconforming content that points to an alternate version that does meet WCAG 2.0 Level 2 success criteria

Applicability

Primary content does not conform to WCAG but alternate versions exist that do conform to WCAG. This technique can only be used if a technology makes it possible to create an accessible link to an alternate version.

This technique is referenced from:

Description

The objective of this technique is to enable users to access alternate content that does conform to WCAG if the primary content, or the default content that users access from a particular URI, does not conform. The alternate page may make some design or functionality compromises in order to conform but should provide the same content that is available in the primary content.

Placing a WCAG conforming link to alternate content at the top of the page allows users to find the link quickly and move to the alternate version. Each page needs a link to the WCAG conforming version of that page, to ensure users can always find it regardless of where they enter the site.

Examples

  • On a Web site, for each page that does not conform to WCAG at the declared level, the first link on the page is called "Alternate version". The target of this link is the alternative version of the page that conforms to WCAG at the declared level.

Tests

Procedure
  1. Identify a page that does not conform to WCAG at conformance Level 2.

  2. Determine if the page contains a link to an alternative version of the page.

  3. Determine if the alternative version conforms to WCAG at conformance Level 2.

Expected Results
  • Both #2 and #3 are true.


5. HTML Techniques


H1: Adding the dir attribute to a block level element to change its directionality

Applicability

(X)HTML

This technique is referenced from:

User Agent and Assistive Technology Support Notes

The following behaviors can only be expected in Internet Explorer 5 if the dir attribute is on the html element, rather than the body element:

  • The OLE/COM ambient property of the document is set to AMBIENT_RIGHTTOLEFT

  • The document direction can be toggled through the document object model (DOM) (document.direction="ltr/rtl")

  • An HTML Dialog will get the correct extended windows styles set so it displays as a RTL dialog on a Bidi enabled system.

  • If the document has vertical scrollbars, they will be used on the left side if dir="rtl".

  • Although the use of the dir attribute is permitted on the body element to identify the text direction of the document, use of the dir attribute on the html element is recommended.

Description

The objective of this technique is to identify changes in the text direction of text in a document by providing the dir attribute on block level elements. The dir attribute allows assistive technology to render the content of the element in its intended order.

The CSS display property can be used to display inline elements as block-level elements or block-level elements as inline elements with the values block or inline, respectively. When CSS is used to display an inline element without a dir attribute as a block-level element, it inherits the value of the dir attribute of its nearest parent block element that specifies text direction.

Examples

Example 1

In a left-to-right Spanish document, this example defines the text direction of a Hebrew blockquote to be right-to-left.

<html  lang="es" xmlns="http://www.w3.org/1999/xhtml">   
<body>    
<blockquote lang="he" dir="rtl"> 
<!-- Hebrew quote -->  
<blockquote> 
</body>
</html>

Resources

Tests

Procedure

For each element in the document:

  1. Examine the text direction of text in the document.

  2. If the text direction is right-to-left, check that for the nearest parent element that has a dir attribute, the attribute has the value "rtl".

  3. If the text direction is left-to-right, check that there is no parent element with a dir attribute, or that for the nearest parent element that has a dir attribute, the attribute has the value "ltr".

Expected Results
  • Checks #2 and #3 are true for all text.


H2: Combining adjacent image and text links for the same resource

Applicability

(X)HTML documents that contain links.

This technique is referenced from:

Description

This objective of this technique is to avoid unnecessary duplication that occurs when adjacent text and iconic versions of a link are contained in a document.

Many kinds of links have both a text and iconic link adjacent to each other. Often the text and the icon link are rendered in separate links, in part to create a slight visual separation from each other. Visually they appear to be the same link, but they are experienced by many people as two identical links and this can be confusing. To avoid this, some authors omit alternative text from the image, but this would fail Success Criterion 1.1.1 because the text alternative would not serve the same purpose as the graphical link. The preferred method to address this is to put the text and image together in one link, and provide null alternative text on the image to eliminate duplication of text.

Sometimes the text and the icon link are rendered in separate, adjacent table cells to facilitate page layout. Note that CSS, rather than a layout table, is preferred to ensure the proper layout. If CSS is used, this technique can be applied to combine the links.

Examples

Example 1

This example demonstrates a failure to apply this technique. An icon and text link are side by side. The text alternative for the image is the same as the text link beside it, leading to a "stutter" effect as the link is read twice.

 <a href="products.html">
   <img src="icon.gif" alt="Products page" />
 </a>
 <a href="products.html">
   Products page
 </a>
Example 2

This example demonstrates a failure to apply this technique. An icon and text link are side by side. In an attempt to remove the "stutter" the text alternative for the image is null. However, now one of the links has an unknown destination, which is its own link text problem.

 <a href="products.html">
   <img src="icon.gif" alt="" />
 </a>
 <a href="products.html">
   Products page
 </a>
Example 3

The icon and text are contained in the same a element.

 <a href="products.html">
   <img src="icon.gif" alt="" />
   Products page
 </a>
Example 4

A link contains an icon and text, and the site help refers to the icon. The img has a text alternative which is the name used for the icon in the site help, which describes clicking the home page icon.

<a href="foo.htm">
  <img src="house.gif" alt="home page icon"/>
  Go to the home page
</a>

Resources

Tests

Procedure

For each a in the content that contains an img element:

  1. Check that there is no adjacent a element that has the same href attribute and the same description

For each a in the content that is contained in a table:

  1. Check that there is no a element in an adjacent table cell that has the same href attribute and the same description

Expected Results
  • All checks above are true.


H4: Creating a logical tab order through links, form controls, and objects

Applicability

HTML 4.01, XHTML 1.x

This technique is referenced from:

Description

The objective of this technique is to provide a logical tab order when the default tab order does not suffice. Often, placing the interactive elements in an order that follows sequences and relationships within the content is sufficient and this technique is not necessary. It can be very easy to introduce usability bugs when setting the tab order explicitly.

In some cases, the author may want to specify a tab order that follows relationships in the content without following the order of the interactive elements in the code. In these cases, an alternative order can be specified using the tabindex attribute of the interactive element. The tabindex is given a value between 0 and 32767.

When the interactive elements are navigated using the tab key, the elements are given focus in increasing order of the value of their tabindex attribute. Elements that have a tabindex value higher than zero will receive focus before elements without a tabindex or a tabindex of 0. After all of the elements with a tabindex higher than 0 have received focus, the rest of the interactive elements are given focus in the order in which they appear in the Web unit.

Examples

Example 1

A genealogical search form searches for marriage records. The search form includes several input fields for the bride and the groom. The form is marked up using a data table that includes the fields of the groom in the first column and the fields of the bride in the second column. The order in the content is row by row but the author feels it is more logical to navigate the form column by column. This way, all the groom's criteria can be filled in before moving on to the bride's criteria. The tabindex attributes of the input fields are used to specify a tab order that navigates column by column.

<form action="#" method="post">
 <table summary="the first column contains the search criteria 
  of the groom, the second column the search criteria of 
  of the bride">
 <caption>Search for marriage records</caption>
 <tr>
   <th>Search criteria</th>
   <th>Groom</th>
   <th>Bride</th>
 </tr>
 <tr>
  <th>First name</th>
  <td><input type="text" size="30" value="" name="groomfirst" 
      title="First name of the groom" tabindex="1"></td>
  <td><input type="text" size="30" value="" name="bridefirst" 
       title="First name of the bride" tabindex="4"></td>
 </tr>
 <tr>
  <th>Last name</th>
  <td><input type="text" size="30" value="" name="groomlast" 
      title="Last name of the groom" tabindex="2"></td>
  <td><input type="text" size="30" value="" name="bridelast" 
      title="Last name of the bride" tabindex="5"></td>
 </tr>
 <tr>
  <th>Place of birth</th>
  <td><input type="text" size="30" value="" name="groombirth" 
      title="Place of birth of the groom" tabindex="3"></td>
  <td><input type="text" size="30" value="" name="bridebirth" 
      title="Place of birth of the bride" tabindex="6"></td>
 </tr>
</table>
</form>
Example 2

A web page contains a search field in the upper right corner. The field is given tabindex="1" so that it will occur first in the tab order, even though it is not first in the content order.

Example 3

Tabindex values need not be sequential nor must they begin with any particular value. The values do not have to be unique. Elements that have identical tabindex values are navigated in the order they appear in the character stream. So in the following example, the tab order would be one, three, two, four.

 <a href="" tabindex="1">one</a>
 <a href="" tabindex="2">two</a>
 <a href="" tabindex="1">three</a>
 <a href="" tabindex="2">four</a>

In sections of the content where the tab order follows the content order, it can be less error prone to give all elements the same tabindex value rather than specifying a different number for each element. Then it is easy to rearrange those elements or add new elements and maintain a logical tab order.

  <a href="xxx" tabindex = "1">First link in list</a>
  <a href="xxx" tabindex = "1">Second link in list</a>
  <a href="xxx" tabindex = "1">Link that was added long 
  after the original list was created</a>
  <a href="xxx" tabindex = "1">Third link in list</a>
  ...
  <a href="xxx" tabindex = "1">Twentieth link in list</a>

Resources

Tests

Procedure
  1. Check if tabindex is used

  2. If tabindex is used, check that the tab order specified by the tabindex attributes follows relationships in the content.

Expected Results
  • Check #2 is true.


H20: Identifying the purpose of a link using link text and text associated with the parent element of the link

Applicability

(X)HTML

This technique is referenced from:

User Agent and Assistive Technology Support Notes

JAWS 5.0 and later includes the following keystrokes:

  • alt+leftArrow: read previous sentence

  • alt+rightArrow: read next sentence

  • alt+NumPad 5: read current sentence

  • Ctrl+NumPad5: read current paragraph

The "read current sentence" keystroke supports examples 1, 2, and 4 below. If alt+numPad5 is pressed when a link has focus, the sentence is read without changing the focus.

The "read current paragraph" keystroke supports Example 3 below. If Ctrl+NumPad 5 is pressed when the link has focus, the entire paragraph is read without changing the focus.

Window-Eyes 5.5 has hotkeys to read the current sentence and current paragraph; thus Window-Eyes 5.5 supports the examples listed below.

The "speak parent element" command in Fire Vox (Ctrl+Shift+u) supports Example 3. This keystroke works without changing the focus. Fire Vox is a free screen reader designed specifically for Firefox 1.0 and later. It supports Windows, Macintosh, and Linux.

Description

The objective of this technique is to identify the purpose of a link from its context by associating the link with its text and with text that is associated with the parent element of the link. The purpose of the link is identified by interpreting the link in the context of the text associated with its parent element.

Note that only the text associated with the immediate parent of the link is used to provide the context for the link. It may not be possible to mark up complex content in a way that includes all the necessary context for a link in its structural parent. In this situation, another technique must be used to identify the purpose of the link.

Examples

Example 1: Explanation of a link precedes the link
<p>...a technology developed by the World Wide Web Consortium, 
<a href="http://www.w3.org">http://www.w3.org">www.w3.org</a>.</p>
Example 2: Links to multiple versions of a document
<p>For prerequisites, please consult the University Course Catalog 
 (<a href="http://MyUniversity.edu/CourseCatalog.html">HTML version</a>, 
  <a href="http://MyUniversity.edu/CourseCatalog.pdf">PDF version</a>).
 </p>
Example 3: Link to the rest of an article
<p>The 12th Annual International Leadership Conference, New Leadership  
  Strategies, will be held June 13-15, in Reno, Nevada. According to President 
  Dolores Hamilton, this year's Leadership Conference is expected to be the largest 
  ever for the organization. 
  <a href="http://MyOrg.org/LeadershipConference.html">Read More</a></p>
Example 4: A Movie Website containing trailers and DVDs
<p>Trailers for theatrical releases:
    <ul>
      <li><a href="OurSite/GWTW">Gone With The Wind</a>
           <a href="OurSite/trailers/1122">Trailer</a></li>
      <li><a href="OurSite/Psycho">Psycho</a>
           <a href="OurSite/trailers/1234">Trailer</a></li>
      <li><a href="OurSite/SLIH">Some Like It Hot</a>
           <a href="OurSite/trailers/1466">Trailer</a></li>
     </ul>
  </p>

  <p>New arrivals on DVD:
    <ul>
      <li><a href="OurSite/Potter">Harry Potter and the Goblet of Fire</a>
           <a href="OurSite/DVD/1122">DVD</a></li>
       <li><a href="OurSite/Narnia">The Chronicles of Narnia: The Lion, 
            The Witch, and The Wardrobe</a>
           <a href="OurSite/DVD/9876">DVD</a></li>
      <li><a href="OurSite/Pirates">Pirates of the Carribean</a>
           <a href="OurSite/DVD/1466">Trailer</a></li>
    </ul>
  </p>
Example 5: (failure) A news site

The home page of a news site includes links to many current news articles. Each news item consists of a heading followed by the first 25 words of the article and a link that says “Read more…" Visually, it is clear that each "Read more..." link goes to the full article for the headline above the link. In the source document, the headline and following text are in separate elements, and the link is an item in a unordered list that is separate from the elements that contain the headline and the text. The parent element of the link is the list item. Assistive technology does not recognize any programmatic association between the “Read more…" link and the preceding text.

<h2>High school basketball team wins state championship.</h2>
<p>In a stunning upset, the Hamilton girls basketball team beat 
   favored Jefferson in the state championship game Saturday night. 
   Coach Bill Smith called this team ...</p>
<ul><li><a href="story1249.html">Read more...</a></li></ul>

Resources

No resources available for this technique.

Tests

Procedure
  1. Check that the purpose of each link can be determined through text associated with the link and with the parent element of the link.

Expected Results
  • Check #1 is true


H21: Not specifying background color, not specifying text color, and not using CSS that changes those defaults

Applicability

HTML and any technology where text and background color are specified separately and browsers can control default colors.

This technique is referenced from:

Description

The objective of this technique is to make sure that users can read text that is presented over a background. With this technique the author avoids having to do any contrast measures by simply not specifying the text color and not specifying the background. As a result the colors of both are completely determined by the user agent.

Examples

Example 1

Example 1: Author specifies neither text color nor background. They also do not use CSS. As a result the user can set his browser defaults to provide the colors and contrasts that work well for them.

Resources

(none currently listed)

Tests

Procedure
  1. Look in all places that text color can be specified

  2. Check that text color is not specified

  3. Look in all areas that background color or image can be specified

  4. Check that no background color or image is specified

Expected Results
  • # 2 and 4 are true


H24: Providing a text alternative for the area element

Applicability

(X)HTML Documents that contain area elements.

This technique is referenced from:

User Agent and Assistive Technology Support Notes

The HTML 4.01 specification explains that the text of the alt attribute is to be displayed when the element can not be rendered normally. Thus, visual User Agents will display the alt attribute text when images are not displayed. The title attribute is meant to provide additional information. User Agents generally will display the title attribute text when the mouse is placed over the element containing the title attribute. Internet Explorer will display the alt text on mouse-over if there is no title text. The Firefox and Opera browsers only display the title text on mouse-over and do not use the alt attribute text for this purpose. Thus, if you want the alt attribute text visible on mouse-over, also include the text using the title attribute.

Description

The objective of this technique is to provide text alternatives that serve the same purpose as the selectable regions of an image map. An image map is an image divided into selectable regions defined by area elements. Each area is a link to another Web unit or another part of the current Web unit. The alt attribute of each area element serves the same purpose as the selectable area of the image.

Examples

Example 1

This example uses the alt attribute of the area element to provide text that describes the purpose of the image map areas.

<img src="welcome.gif" usemap="#map1" 
    alt="Areas in the library" /> 
<map id="map1" name="map1">
  <area shape="rect" coords="0,0,30,30"
    href="reference.html" alt="Reference" />
  <area shape="rect" coords="34,34,100,100"
    href="media.html" alt="Audio visual lab" />
</map>

Resources

Tests

Procedure

For each area element in an image map:

  1. Check that the area element has an alt attribute.

  2. Check that the text alternative serves the same purpose as the part of image map image referenced by the area element of the imagemap.

Expected Results
  • The above checks are true.


H25: Providing a title using the title element

Applicability

(X)HTML

This technique is referenced from:

Description

All (X)HTML documents, including those in individual frames in a frameset, have a title element in the head section that defines in a simple phrase the purpose of the document. This helps users to orient themselves within the site quickly without having to search for orientation information in the body of the page.

Note that the (mandatory) title element, which only appears once in a document, is different from the title attribute, which may be applied to almost every HTML 4.01 element.

Examples

Example 1

This example defines a document's title.

<html xmlns="http://www.w3.org/1999/xhtml">   
   <head>     
      <title>The World Wide Web Consortium</title>     
   </head>   
   <body>     
      ...   
   </body> 
</html>

Resources

Tests

Procedure
  1. Examine the source code of the HTML document and check that a non-empty title element appears in the head section.

  2. Check that the title element describes the document.

Expected Results
  • Checks 1 and 2 are true.


H27: Providing text and non-text alternatives for object

Applicability

Documents that load media with the object element, when the media format is not in the baseline.

This technique is referenced from:

Description

If object is used, provide a text alternative in the content of the element:

Examples

Example 1

This example shows a text alternative for a Java applet using the object element.

 
<object classid="java:Press.class" width="500" height="500">
  As temperature increases, the molecules in the balloon...
</object>
Example 2

This example takes advantage of the fact the object elements may be nested to provide for alternative representations of information.

 
<object classid="java:Press.class" width="500" height="500">
  <object data="Pressure.mpeg" type="video/mpeg">
    <object data="Pressure.gif" type="image/gif">
      As temperature increases, the molecules in the balloon...
    </object>
  </object>
</object>

Resources

Tests

Procedure

H28: Providing definitions for abbreviations by using the abbr and acronym elements

Applicability

HTML 4.x, XHTML 1.x

This technique is referenced from:

User Agent and Assistive Technology Support Notes

Most graphical user agents render text enclosed within an abbr or acronym element with a dotted line below or surrounding it. In addition, when the mouse hovers over the element, the expansion is displayed as a tool tip.

In Internet Explorer 6 and below, items marked using the abbr element are not displayed with any additional formatting nor does the expanded version display as a tooltip when the mouse hovers over the item. Future versions are expected to provide these features for the abbr element.

JAWS 6.2, WindowEyes 5.0, and Home Page Reader 3.0 support the abbr and acronym elements. They can all be set to speak the title attribute when these elements are encountered. Within a given product the abbr and acronym elements are rendered the same way.

Description

The objective of this technique is to provide expansions or definitions for abbreviations by using the abbr and acronym elements.

It is always appropriate to use the abbr element for any abbreviation, including acronyms and initialisms. When using HTML 4.01, XHTML 1.0 or XHTML 1.1, initialisms and acronyms may be marked up using the acronym element. XHTML 2.0 proposes eliminating the acronym element in favor of the more general abbr element.

Examples

Example 1: Using abbr element to expand abbreviations.
<p>Sugar is commonly sold in 5 <abbr title="pound">lb.<abbr> bags.</p>
<p>Welcome to the <abbr title="World Wide Web">WWW</abbr>!</p> 
Example 2: Using abbr element to define abbreviations.
<p>Tasini <abbr title="and others">et al.</abbr> <abbr title="versus">v.</abbr>
The New York Times <abbr title="and others">et al.</abbr> is the landmark lawsuit 
brought by members of the National Writers Union against ......</p>
Example 3: Using the acronym element to expand an initialism
<p>The use of <acronym title="Keep It Simple Stupid">KISS</acronym> became popular in ...</p>
Example 4: Using the acronym element to expand an acronym
<p><acronym title="World Wide Web">WWW</acronym></p>

Resources

Tests

Procedure
  1. Check that an expansion or definition is provided for each abbreviation via abbr or acronym.

Expected Results
  • Check #1 is true.


H30: Providing link text that describes the purpose of a link for anchor elements

Applicability

(X)HTML documents that contain links, that is, <a href> elements.

This technique is referenced from:

User Agent and Assistive Technology Support Notes

The HTML 4.01 specification explains that the text of the alt attribute is to be displayed when the element can not be rendered normally. Thus, visual User Agents will display the alt attribute text when images are not displayed. The title attribute is meant to provide additional information. User Agents generally will display the title attribute text when the mouse is placed over the element containing the title attribute. Internet Explorer will display the alt text on mouse-over if there is no title text. The Firefox and Opera browsers only display the title text on mouse-over and do not use the alt attribute text for this purpose. Thus, if you want the alt attribute text visible on mouse-over, also include the text using the title attribute.

Description

The objective of this technique is to describe the purpose of a link by providing descriptive text as the content of the a element. The description lets a user distinguish this link from other links in the Web unit and helps the user determine whether to follow the link. The URI of the destination is generally not sufficiently descriptive.

When an image is the only content of a link, the text alternative for the image describes the unique function of the link.

When the content of a link contains both text and one or more images, if the text is sufficient to describe the purpose of the link, the images may have an empty text alternative. (See Using null alt text and no title attribute on img elements for images that AT should ignore.) When the images convey information beyond the purpose of the link, they must also have appropriate alt text.

Examples

Example 1

Describing the purpose of a link in HMTL in the text content of the a element.

<a href="routes.html">
  Current routes at Boulders Climbing Gym
</a>
Example 2

Using the alt attribute for the img element to describe the purpose of a graphical link.

<a href="routes.html">
   <img src="topo.gif" alt="Current routes at Boulders Climbing Gym" /> 
</a> 
Example 3

Using an empty alt attribute when the anchor (a) element contains text that describes the purpose of the link in addition to the img element. Note that the link text will appear on the page next to the image.

<a href="routes.html">
  <img src="topo.gif" alt="" />
  Current routes at Boulders Climbing Gym
</a>
Example 4

A link contains an icon and text, and the site help refers to the icon. The img has a text alternative which is the name used for the icon in the site help, which describes clicking the home page icon.

<a href="foo.htm">
  <img src="house.gif" alt="home page icon"/>
  Go to the home page
</a>

Resources

Tests

Procedure

For each link in the content that uses this technique:

  1. Check that text or a text alternative for non-text content is included in the a element

  2. If an img element is the only content of the a element, check that its text alternative describes the purpose of the link

  3. If the a element contains one or more img element(s) and the text alternative of the img element(s) is empty, check that the text of the link describes the purpose of the link

  4. If the a element only contains text, check that the text describes the purpose of the link

Expected Results
  • The above checks are true.


H32: Providing submit buttons

Applicability

Content that includes form controls.

This technique is referenced from:

Description

The objective of this technique is to provide a mechanism that allows users to explicitly request changes of context. The intended use of a submit button is to generate an HTTP request that submits data entered in a form, so it is an appropriate control to use for causing a change of context.

Examples

Example 1:

This is a basic example of a form with a submit button.

<form action="http://www.example.com/cgi/subscribe/" method="post"><br /> 
 <p>Enter your e-mail address to subscribe to our mailing list.</p><br /> 
 <label for="address">Enter email address:</label><input type="text" 
 id="address" name="address" /> 
 <input type="submit" value="Subscribe" /><br /> 
</form> 
Example 2:

The following example uses a server-side script (specified in the action attribute) that redirects the user to the requested page.

  
  <form action="http://www.example.com/cgi/redirect/" method="get"><br /> 
    <p>Navigate the site.</p><br /> 
    <select name="dest"><br /> 
      <option value="/index.html">Home</option/><br /> 
      <option value="/blog/index.html">My blog</option/><br /> 
      <option value="/tutorials/index.html">Tutorials</option/><br /> 
      <option value="/search.html">Search</option/><br /> 
    </select><br /> 
  <input type="submit" value="Go!" /><br /> 
  </form> 

Resources

Tests

Procedure
  1. Find all forms in the content

  2. For each form, check that it has a submit button (input type="submit")

Expected Results
  • #2 is true


H33: Supplementing link text with the title attribute

Applicability

(X)HTML

This technique is referenced from:

User Agent and Assistive Technology Support Notes

  • User agents will display a tool tip when the mouse hovers above an anchor element containing a title attribute.

  • Assistive technologies provide different levels of support for speaking the title attribute for an anchor element.

    • JAWS 7.0 will speak either the link text or the title attribute for a link depending upon a JAWS setting. This setting can be changed temporarily or permanently within JAWS.

    • WindowEyes 5.5 has a hot key, ins-E, that will speak additional information, including the title attribute, for the item with focus.

    • Home Page Reader 3.04 will speak the title attribute of any element with focus when the control-shift-F1 keys are pressed simultaneously.

Description

The objective of this technique is to demonstrate how to use a title attribute on an anchor element to provide additional text describing a link. The title attribute is used to provide additional information to help clarify or further describe the purpose of a link.

Examples

Example 1: Clarifying the purpose of a link
<a href="http://www.newsorg.com/2005/WORLD/africa/08/25/kenya.elephants.ap/index.html" 
   title="Read more about failed elephant evacuation">
   Evacuation Crumbles Under Jumbo load
</a>
Example 2: A link that opens in a new window

In HTML 4.01 the target="_blank" attribute can be used on an anchor element to indicate that the URI specified by the href attribute will be opened in a new window. This example shows using the title attribute of the anchor element to provide information that the link will be opened in a new window.

<a href="http://www.newsorg.com.com/subscribe.html" 
     target="_blank" 
     title="link opens in new window">
     Subscribe to email notifications about breaking news
</a>

Resources

No resources available for this technique.

Tests

Procedure

Examine the source code for anchor elements.

  1. For each anchor element that has a title attribute, check that the title attribute together with the link text describes the purpose of the link.

Expected Results
  • Check #1 is true.


H34: Using a Unicode right-to-left mark (RLM) or left-to-right mark (LRM) to mix text direction inline

Applicability

(X)HTML

This technique is referenced from:

User Agent and Assistive Technology Support Notes

Description

The objective of this technique is to use Unicode right-to-left marks and left-to-right marks to override the HTML bidirectional algorithm when it produces undesirable results. This may be necessary, for instance, when placing neutral characters such as spaces or punctuation between different directional text runs. The concepts used in this technique are described in What you need to know about the bidi algorithm and inline markup.

The character entities for these markers are

  • left-to-right mark: &lrm; or &#8206; (U+202A)

  • right-to-left mark: &rlm; or &#8207; (U+202B)

Examples

Example 1

This example shows an Arabic phrase in the middle of an English sentence. The exclamation point is part of the Arabic phrase and should appear on its left. Because it is between an Arabic and Latin character and the overall paragraph direction is LTR, the bidirectional algorithm would position it to the right of the Arabic phrase. Inserting a Unicode right-to-left mark (via the HTML character entity ‏) after the exclamation mark positions it correctly.

<p>The title is "مفتاح معايير الويب!&rlm;" in Arabic.</p>

The following is a working example of the code above:

The title is "مفتاح معايير الويب!‏" in Arabic.

Resources

Tests

Procedure
  1. Examine the source for places where text changes direction.

  2. When text changes direction, check whether neutral characters such as spaces or punctuation occur adjacent to text that is rendered in the non-default direction.

  3. When #2 is true and the HTML bidirectional algorithm would produce the wrong placement of the neutral characters, check whether the neutral characters are followed by Unicode right-to-left or left-to-right marks that cause neutral characters to be placed as part of the preceding characters.

Expected Results
  • Check #3 is true.


H35: Using alt attributes on applet elements

Applicability

HTML Documents that load Java applets where applet is not deprecated.

This technique is referenced from:

Description

Use the alt attribute to label an applet.

Examples

Example 1

Resources

Tests

Procedure
  1. View the alt attribute value of the applet element.

  2. Check that each applet element contains a text alternative for the applet.

Expected Results
  • #2 is true


H36: Using alt attributes on images used as submit buttons

Applicability

Applies to content using image-based submit buttons.

This technique is referenced from:

Description

For input elements of type 'image', the alt attribute of the input element is used to provide a functional label. This label indicates the button’s function, not attempt to describe the image. The label is especially important if there are multiple submit buttons on the page that each lead to different results.

The input element is used to create many kinds of form controls. Although the HTML DTD permits the alt attribute on all of these, it should be used only on image submit buttons. User agent support for this attribute on other types of form controls is not well defined, and other mechanisms are used to label these controls.

Examples

Example 1

An input element with an alt attribute

<form action="http://example.com/prog/text">
  http://example.com/prog/text-read" method="post">
  <input type="image" name="submit" src="button.gif" alt="Submit" />
</form>

Resources

Tests

Procedure
  1. For all input elements that have a type attribute value of "image", check for the presence of an alt attribute.

Expected Results
  • #1 is true


H37: Using alt attributes on img elements

Applicability

Documents that load images, when the image format is not in the baseline.

This technique is referenced from:

Description

When using the img element, specify a short text alternative with the alt attribute. Note. The value of this attribute is referred to as "alt-text".

Examples

Example 1

The image contains alt text that plays the same function on the page as the image. Note that it does not necessarily describe the visual characteristics of the image itself.

 
<img src="companylogo.gif" alt="Company Name">

Resources

Tests

Procedure

H39: Using caption elements to associate data table captions with data tables

Applicability

HTML, XHTML data tables

This technique is referenced from:

Description

The objective of this technique is to identify data tables using the caption element. The caption is shown on the screen and reported by screen readers. This technique may be a good choice when tables are difficult to identify, for example, when text immediately preceding the table does not refer directly to the table, or when there are multiple tables in the same Web unit.

The caption element is similar to a heading. Unlike a heading element (h1-h6), however, the caption element is part of the table itself. Therefore, using caption ensures that information identifying the table is always kept with the table.

The caption element may be used whether or not the table includes a summary attribute. The caption element identifies the table whereas the summary attribute gives an overview of the purpose or explains how to navigate the table. If both are used, the caption should not duplicate information in the summary.

Use of layout tables is not recommended. However, if layout tables are used, then the caption element is not recommended. The purpose of a layout table is simply to control the placement of content; the table itself is “transparent" to the user. A caption would “break" this transparency by calling attention to the table.

Examples

Example 1: An appointment calendar with a caption
<table>
<caption>Schedule for the week of March 6</caption>
...</table>

Resources

Tests

Procedure
  1. Check for layout tables: determine whether the content has a relationship with other content in both its column and its row

    1. If “no," the table is a layout table.

    2. If “yes," the table is a data table.

  2. Check if the table includes a caption element.

  3. If the table includes a caption element, check that the caption identifies the table.

  4. Check if a summary attribute is present for the table element.

  5. If both a summary attribute and a caption element are present, check that the summary does not duplicate the caption.

Expected Results
  • For layout tables, #2 is false.

  • For data tables, #3 and #5 are true.


H40: Using definition lists

Applicability

HTML 4.x, XHTML 1.x

This technique is referenced from:

User Agent and Assistive Technology Support Notes

Description

The objective of this technique is to provide the definitions of words or phrases by presenting them in a definition list. The list is marked up using the dl element. Within the list, each term is put in a separate dt element, and its definition goes in the dd element directly following it. The title attribute can be used to provide additional information about the definition list.

Using dl, dt, and dd ensures that relationships between terms and their definitions are preserved if the presentation format changes and that the list of terms and definitions is treated as a unit.

Definition lists are easiest to use when the definitions are put in alphabetical order. Definition lists are typically used in a glossary.

Examples

Example 1

A list of definitions of nautical terms used on a website about sailing.

<dl title="Nautical terms">
<dt>Knot</dt>
<dd>
<p>A <em>knot</em> is a unit of speed equaling 1 
nautical mile per hour (1.15 miles per hour or 1.852 
kilometers per hour).</p>
</dd>
<dt>Port</dt>
<dd>
<p><em>Port</em> is the nautical term (used on 
boats and ships) that refers to the left side
of a ship, as perceived by a person facing towards 
the bow (the front of the vessel).</p>
</dd>
<dt>Starboard</dt>
<dd>
<p><em>Starboard</em> is the nautical term (used 
on boats and ships) that refers to the right 
side of a vessel, as perceived by a person 
facing towards the bow (the front of the vessel).</p>
</dd>
</dl>

Resources

Tests

Procedure

For any set of words and their definitions that have the appearance of a list:

  1. Check that the list is contained within a dl element.

  2. Check that each word defined in the list is contained within a dt element.

  3. Check that the definition for each word appears in the dd element immediately following the word's dt element .

Expected Results
  • All checks above are true.


H42: Using h1-h6 to identify headings

Applicability

(X)HTML

This technique is referenced from:

Description

The objective of this technique is to use HTML heading markup to convey the structure of the content. Heading markup can be used:

  • to distinguish the main content from navigation bars, graphical banners, footers, etc.

  • to show the organization of material within the main content

In HTML 4.01 and XHTML 1.x, heading markup is designed to convey logical hierarchy, and heading elements include numbers (h1 through h6). Skipping levels in the sequence of headings may create the impression that the structure of the document has not been properly thought through or that specific headings have been chosen for their visual rendering rather than their meaning. CSS (Cascading Style Sheets) can be used to change the way headings look or sound.

Since headings indicate the start of important sections of content, it is possible for users with assistive technology to jump directly to the appropriate heading and begin reading the content. This significantly speeds interaction for users who would otherwise access the content slowly.

Using headings merely to change the appearance of text does not convey the organization of the content, and may confuse users who use headings to perceive structure or rely on them for navigation. Conversely, while applying bold format, or even "class=heading", can result in the visual display of a heading, assistive technologies will not recognize such text as headings.

Examples

Example 1: Headings show the overall organization of the content

In this example, heading markup is used to make the navigation and main content sections perceivable.

  <!-- Logo, banner graphic, search form, etc.  -->
  <h2>Navigation</h2>
    <ul>
      <li><a href="about.htm">About us</a></li>
      <li><a href="contact.htm">Contact us</a></li>
       ...
    </ul>
  <h2>All about headings</h2>
   <!-- Text, images, other material making up the main content... -->
Example 2: Headings show the organization of material within the main content

Note that in HTML 4.01 and XHTML 1.x, heading elements only mark the beginning of sections; they do not contain them as element content.

<html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <title>Cooking techniques</title>  
  </head>   
  <body>     
    <h1>Cooking techniques</h1>     
    <p>       
      ... some text here ...     
    </p>           
    <h2>Cooking with oil</h2> 
    <p> 
        ... text of the section ...     
    </p>           
    <h2>Cooking with butter</h2>       
    <p>
        ... text of the section ...     
    </p>   
  </body> 
</html>

Resources

Tests

Procedure
  1. Check that heading markup is used when content is a heading.

  2. Check that heading markup is not used when content is not a heading.

Expected Results
  • Checks #1 and #2 are true.


H43: Using id and headers attributes to associate data cells with header cells in data tables

Applicability

HTML 4.01 and XHTML 1.x

This technique is referenced from:

Description

The objective of this technique is to associate each data cell (in a data table) with the appropriate headers. This technique adds a headers attribute to each data cell (td element). It also adds an id attribute to any cell used as a header for other cells. The headers attribute of a cell contains a list of the id attributes of the associated header cells. If there is more than one id, they are separated by spaces.

This technique is used when data cells are associated with more than one row and/or one column header. This allows screen readers to speak the headers associated with each data cell when the relationships are too complex to be identified using the th element alone or the th element with the scope attribute. Using this technique also makes these complex relationships perceivable when the presentation format changes.

This technique is not recommended for layout tables since its use implies a relationship between cells that is not meaningful when tables are used for layout.

Examples

Example 1: A table with multiple rows of headers
  <table>
   <tr>
     <th rowspan="2" id="h">Homework</th>
     <th colspan="3" id="e">Exams</th>
     <th colspan="3" id="p">Projects</th>
   </tr>
   <tr>
     <th id="e1" headers="e">1</th>
     <th id="e2" headers="e">2</th>
     <th id="ef" headers="e">Final</th>
     <th id="p1" headers="p">1</th>
     <th id="p2" headers="p">2</th>
     <th id="pf" headers="p">Final</th>
   </tr>
   <tr>
    <td headers="h">15%</td>
    <td headers="e e1">15%</td>
    <td headers="e e2">15%</td>
    <td headers="e ef">20%</td>
    <td headers="p p1">10%</td>
    <td headers="p p2">10%</td>
    <td headers="p pf">15%</td>
   </tr>
  </table>

Resources

Tests

Procedure
  1. Check for layout tables: determine whether the content has a relationship with other content in both its column and its row. If “no," the table is a layout table. If “yes," the table is a data table.

  2. For data tables, check that any cell that is associated with more than one row and/or one column header contains a headers attribute that lists the id for all headers associated with that cell.

  3. For data tables where any cell contains an id or headers attribute,

    1. Check that each id listed in the headers attribute of the data cell matches the id attribute of a cell that is used as a header element

    2. Check that the headers attribute of a data cell contains the id attribute of all headers associated with the data cell

    3. Check that all ids are unique (that is, no two elements in the page have the same id)

Expected Results
  • If table is a layout table, no cells contain headers or id attributes

  • If table is a data table and any cell contains an id attribute, checks #3.1, #3.2, and #3.3 are true.

  • If table is a data table and any cell is associated with more than one row and/or one column header, check #2 is true.


H44: Using label elements to associate text labels with form controls

Applicability

HTML, XHTML controls that use external labels

This technique is referenced from:

User Agent and Assistive Technology Support Notes

The HTML specification allows both implicit and explicit labels. However, many assistive technologies do not correctly handle implicit labels (for example, <label>First name <input type="text" name="firstname"></label>).

Description

The objective of this technique is to use the label element to explicitly associate a form control with a label. A label is attached to a specific form control through the use of the for attribute. The value of the for attribute must be the same as the value of the id attribute of the form control.

The id attribute may have the same value as the name attribute, but both must be provided, and the id must be unique in the Web unit.

Note that the label is positioned after input elements of type="checkbox" and type="radio".

Note: Elements that use explicitly associated labels are:

  • input type="text"

  • input type="checkbox"

  • input type="radio"

  • input type="file"

  • input type="password"

  • textarea

  • select

Note 1: The label element is not used for the following:

  • Submit and Reset buttons (input type="submit" or input type="reset")

  • Image buttons (input type="image")

  • Hidden input fields (input type="hidden")

  • Script buttons (button elements or <input type="button">)

Note 2: Labels for these elements are implicitly associated via the value attribute (for Submit and Reset buttons), the alt attribute (for image buttons), or element content (button).

Examples

Example 1: A text input field

The text field in the example below has the explicit label of "First name:". The label element's for attribute matches the id attribute of the input element.

<label for="firstname">First name:</label> 
<input type="text" name="firstname" id="firstname" />
Example 2: A checkbox
<input type="checkbox" id="markuplang" name="computerskills" checked="checked">
<label for="markuplang">HTML</label>

Resources

Tests

Procedure

For all input elements of type text, file or password, for all textareas and for all select elements in the Web unit:

  1. Check that there is a label element with at least one printable character before the input element

  2. Check that the for attribute of the label element matches the id of the input element

For all input elements of type checkbox or radio in the Web unit::

  1. Check that there is a label element with at least one printable character after the input element

  2. Check that the for attribute of the label element matches the id of the input element

Expected Results
  • All checks above are true.


H45: Using longdesc

Applicability

(X)HTML Documents that include images that can not be described in a short text alternative.

User Agent and Assistive Technology Support Notes

  • Some older assistive technologies do not support the longdesc attribute. Supported in leading Assistive technologies now.

This technique is referenced from:

Description

The objective of this technique is to provide information in a file designated by the longdesc attribute when a short text alternative does not adequately convey the function or information provided in the image. The longdesc attribute is a URI, the target of which contains a long description of the non-text content.

Examples

Example 1

Resources

Tests

Procedure
  1. Check that a longdesc attribute exists.

  2. Check that the link in the longdesc attribute is valid

  3. Check that the long description describes the original non-text content associated with it.

Expected Results
  • #1 through #3 are all true


H46: Using noembed with embed

Applicability

Documents that load plugins with the embed element.

This technique is referenced from:

User Agent and Assistive Technology Support Notes

Note: Although embed is widely supported in user agents - it is not a valid part of HTML.

Description

The objective of this technique is to provide alternative content for the embed element in a noembed element. The noembed is rendered only if the embed is not supported. While it can be positioned anywhere on the page, it is a good idea to include it as a child element of embed so that it is clear to assistive technologies that a text alternative is associated with the embed element it describes.

Examples

Example 1: noembed is provided inside an embed
<embed
  src="../movies/history_of_rome.mov"
  height="60" width="144" autostart="false">
	<noembed>
		<a href="../transcripts/transcript_history_rome.htm">
		Transcript of "The history of Rome"</a>
	</noembed>
</embed>
Example 2: noembed is provided beside an embed
<embed src="moviename.swf" width="100" height="80"
  pluginspage="http://example.com/shockwave/download/" />
<noembed>
  <img alt="Still from Movie" src="moviename.gif" 
    width="100" height="80" />
</noembed>

Resources

No resources available for this technique.

(none currently listed)

Tests

Procedure
  1. Check if embed element has a child noembed element

  2. Check if embed element has a noembed element that immediately follows it.

Expected Results
  • #1 is true or #2 is true


H48: Using ol, ul and dl for lists

Applicability

HTML, XHTML

This technique is referenced from:

Description

The objective of this technique is to create lists of related items using list elements appropriate for their purposes. The ol element is used when the list is ordered and the ul element is used when the list is unordered. Definition lists (dl) are used to group terms with their definitions. Although the use of this markup can make lists more readable, not all lists need markup. For instance, sentences that contain comma-separated lists may not need list markup.

When markup is used that visually formats items as a list but does not indicate the list relationship, users may have difficulty in navigating the information. An example of such visual formatting is including asterisks in the content at the beginning of each list item and using <br> elements to separate the list items.

Some assistive technologies allow users to navigate from list to list or item to item. Style sheets can be used to change the presentation of the lists while preserving their integrity.

Examples

Example 1: A list showing steps in a sequence

This example uses an ordered list to show the sequence of steps in a process.

<ol>
<li>Mix eggs and milk in a bowl.</li>
<li>Add salt and pepper.</li>
</ol>
Example 2: A grocery list

This example shows an unordered list of items to buy at the store.

<ul>
<li>Milk</li>
<li>Eggs</li>
<li>Butter</li>
</ul>
Example 3: A word and its definition

This example uses a definition list to group a definition with the term that is being defined.

<dl>
<dt>blink</dt>
<dd>turn on and off between .5 and 3 times per second
</dd>
</dl>

Resources

(none currently listed)

Tests

Procedure
  1. Check that content that has the visual appearance of a bulleted list is marked as an unordered list

  2. Check that content that has the visual appearance of a numbered list is marked as an ordered list

  3. Check that content is marked as a definition list when terms and their definitions are presented in the form of a list

Expected Results
  • All the checks above are true.


H49: Using semantic markup to mark emphasized or special text

Applicability

HTML 4.01 and XHTML 1.x

This technique is referenced from:

User Agent and Assistive Technology Support Notes

Some semantic elements are not supported well by assistive technologies. JAWS contains support for blockquote and cite. WindowEyes contains support for blockquote, q and cite.

Description

The objective of this technique is to demonstrate how semantic markup can be used to mark emphasized or special text so that it can be programmatically determined. Using semantic markup to mark emphasized or special text also provides structure to the document. User agents can then make the structure perceivable to the user, for example using a different visual presentation for different types of structures or by using a different voice or pitch in an auditory presentation.

Most user agents will visually distinguish text that has been identified using semantic markup. Some assistive technologies provide a mechanism for determining the characteristics of content that has been created using proper semantic markup.

Examples

Example 1

This example shows how to use the em and strong elements to emphasize text. The em and strong elements were designed to indicate structural emphasis that may be rendered in a variety of ways (font style changes, speech inflection changes, etc.).

...What she <em>really</em> meant to say was, &quot;This is not ok, it is <strong>excellent</strong>!...
Example 2

This example shows using the blockquote element to mark up long quotations which may require paragraph breaks. It also demonstrates the use of the cite element to specify a reference.

<p>The following is an excerpt from the <cite>The Story of my Life</cite> by Helen Keller</p>
 <blockquote>
 <p>Even in the days before my teacher came, I used to feel along the square stiff boxwood
 hedges, and, guided by the sense of smell, would find the first violets and lilies.  
 There, too, after a fit of temper, I went to find comfort and to hide my hot face 
 in the cool leaves and grass.</p>
 </blockquote>
Example 3

Here is the use of the q element to mark up a shorter quotation.

<p>Helen Keller said, <q>Self-pity is our worst enemy and if we yield to it, 
we can never do anything good in the world.</q></p>
Example 4

Superscripts and subscripts are created using the sup and sub elements.

<p>Beth received 1<sup>st</sup> place in the 9<sup>th</sup> grade science competition.</p>
<p>The chemical notation for water is H<SUB>2</SUB>O.</p>

Resources

Tests

Procedure
  1. Examine the content for information that is conveyed through variations in presentation of text.

  2. Check that appropriate semantic markup (such as em, strong, cite, blockquote, quote, sub, and sup) have been used to mark the text that conveys information through variations in text.

Expected Results
  • Check #2 is true.


H50: Using structural elements to group links

Applicability

(X)HTML

This technique is referenced from:

User Agent and Assistive Technology Support Notes

Current assistive technology does not support navigation by div elements.

Description

The objective of this technique is to demonstrate how to group links into logical sets. When links are grouped into logical sets (for example, in a navigation bar or main menu that appears on every page in a site) they should be marked up as a unit. Navigation bars are usually the first thing someone encounters on a page. People who are sighted are often able to ignore navigation parts and start reading the content of the page. Someone using a screen reader must first listen to the text of each link in the navigation bar before reading the interesting content. There are several ways to mark up content so that a user with a screen reader can jump over the navigation bar and avoid reading all of the links.

Group links via one of the following mechanisms (in descending order of preference):

  • ul or ol

  • div

  • map

Examples

Example 1: Using lists to group links

In this example the links are grouped using the ul and li elements.

<a name="categories" id="categories"></a><h2>Product Categories</h2>
<ul class="navigation">
    <item><p><a href="kitchen.html">Kitchen</a></p></item>
    <item><p><a href="bedbath.html">Bed & Bath</a></p></item>
    <item><p><a href="dining.html">Fine Dining</a></p></item>
    <item><p><a href="lighting.html>Lighting</a></p></item>
    <item><p><a href="storage.html">Storage</a><item><p>
</ulist>

CSS can be used to style the list elements, so this technique can be used with a variety of visual appearances.

Here is a style that removes the list bullets and the left padding that creates the indent and flows the individual list elements horizontally.

 ul.navigation {
 list-style: none; 
 padding: 0;
 }
 ul.navigation li {
 display: inline;
 } 

This style removes the list bullets and the left padding and displays the items in a floating block.

 ul.navigation {
 list-style: none; 
 padding: 0;
 }
 ul.navigation li {
 display: block; 
 float: left;
 } 
Example 2: Using div to group links

In this example the links in a breadcrumb trail are grouped within a div.

 <div title="Breadcrumb trail" class="breadcrumb">
   <a href="home.html">Home</a> :
   <a href="technology.html">Web Accessibility</a> :
   <a href="guideline.html">Guidelines</a> :
   1.3
 </div> 

Which will display as Home : Web Accessibility : Guidelines : 1.3

Example 3: Using map to group links

In this example, the map element groups a set of links, the title attribute identifies it as a navigation bar.

 <map title="Navigation Bar">
  <p>
    [<a href="home.html">Home</a>] 
    [<a href="search.html">Search</a>] 
    [<a href="new.html">New and highlighted</a>] 
    [<a href="sitemap.html">Site map</a>]
  </p>
 </map> 

Resources

(none currently listed)

Tests

Procedure

Examine the content for anchor elements which are grouped together with a related purpose.

  1. Check that the anchor elements are grouped using list, div or map elements.

Expected Results
  • Check #1 is true.


H51: Using table markup to present tabular information

Applicability

HTML 4.01, XHTML 1.x

This technique is referenced from:

Description

The objective of this technique is to present tabular information in a way that preserves relationships within the information even when users cannot see the table or the presentation format is changed. Information is considered tabular when logical relationships among text, numbers, images, or other data exist in two dimensions (vertical and horizontal). These relationships are represented in columns and rows, and the columns and rows must be recognizable in order for the logical relationships to be perceived.

Using the HTML table element with the child elements tr, th, and td makes these relationships perceivable. Techniques such as inserting tabs to create columns or using the HTML pre element are purely visual, and visually implied logical relationships are lost if the user cannot see the table or the visual presentation is changed.

Examples

Example 1: A schedule marked up as a simple data table with column and row headers

This example uses markup for a simple data table. The first row shows the days of the week. Time intervals are shown in the first column. These cells are marked with the th element. This identifies the days of the week as column headers and the time intervals as row headers.

Screen readers speak header information that changes as the user navigates the table. Thus, when screen reader users move to left or right along a row, they will hear the day of the week (the column header) followed by the appointment (if any). They will hear the time interval as they move up or down within the same column.

<table>
<tr>
<td> </td>
<th>Monday</th>
<th>Tuesday</th>
<th>Wednesday</th>
<th>Thursday</th>
<th>Friday</th>
</tr>
<tr>
<th>8:00-9:00</th>
<td>Meet with Sam</td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<th>9:00-10:00</th>
<td> </td>
<td> </td>
<td>Doctor Williams</td>
<td>Sam again</td>
<td>Leave for San Antonio</td>
</tr>
</table>

Resources

Tests

Procedure
  1. Check for the presence of tabular information.

  2. For each occurrence of tabular information:

    1. Check that table markup with at least the elements table, tr, th, and td is used.

Expected Results
  • All checks above are true.


H52: Using the body of the applet element

Applicability

(X)HTML Documents that load Java applets.

User Agent and Assistive Technology Support Notes

  • Note that the applet element was officially deprecated effective with HTML 4.0. However, this element remains in wide use on the Internet and is recognized by many user agents and assistive technologies.

This technique is referenced from:

Description

The objective of this technique is to provide a text alternative for content rendered using the <applet> element. This is done by including the alternate text in the body of the applet.

Examples

Example 1

This example shows a text alternative for a Java applet using the applet element.

 <applet code="Press.class" width="500" height="500"> 
                             As temperature increases, the molecules in the balloon... 
                             </applet> 
                            <p>

Resources

  • (none)

(none currently listed)

Tests

Procedure
  1. Locate each applet element and view the child elements of the applet.

  2. Check that each applet element contains a text alternative for the applet.

Expected Results
  • #2 is true


H53: Using the body of the object element

Applicability

Documents that load media with the object element.

This technique is referenced from:

User Agent and Assistive Technology Support Notes

This technique is not supported well by assistive technologies and cross-browser support is irregular.

Description

The objective of this technique is to provide a text alternative for content rendered using the object element. The body of the object element can be used to provide a complete text alternative for the object or may contain additional non-text content with text alternatives.

Examples

Example 1: An object includes a long description that describes it
<object classid="http://www.example.com/analogclock.py">
  <p>Here is some text that describes the object and its operation.</p>
</object>
Example 2: An object includes non-text content with a text alternative
<object classid="http://www.example.com/animatedlogo.py">
  <img src="staticlogo.gif" alt="Company Name" />
</object>
Example 3: The image object has content that provides a brief description of the function of the image
<object data="companylogo.gif" type="image/gif">
  <p>Company Name</p>
</object>

Resources

Tests

Procedure
  1. Check that each object element contains a long description.

Expected Results
  • #1 is true.


H54: Using the dfn element to identify the defining instance of a word

Applicability

HTML 4.x and XHTML 1.x

This technique is referenced from:

User Agent and Assistive Technology Support Notes

Description

The objective of this technique is to use the dfn to mark the use of a word or phrase where it is defined. The dfn element is used to indicate the defining instance of the enclosed term. In other words, it marks the occurrence of the term where the term is defined. Note that it encloses the term, not the definition. This technique would be used in combination with Using inline definitions to provide the definition.

Examples

Example 1

The following code snippet demonstrates the use of the dfn element.

<p>The Web Content Accessibility Guidelines require that non-text content 
has a text alternative, unless the non-text content is purely decorative 
or a spacer image. <dfn>Non-text content</dfn> is content that is not 
represented by a Unicode character or sequence of Unicode characters 
when rendered in a user agent according to the formal specification of the 
content type; this includes ASCII Art, which is a pattern of characters.</p>

Resources

Tests

Procedure
  1. Identify all words that are defined inline in the text, that is, where the definition occurs in a sentence near an occurrence of the word.

  2. Check that each word that is defined inline is contained in a dfn element.

Expected Results
  • Check #2 is true.


H55: Using the dir attribute of the html element

Applicability

(X)HTML

This technique is referenced from:

User Agent and Assistive Technology Support Notes

The following behaviors can only be expected in Internet Explorer 5 if the dir attribute is on the html element, rather than the body element:

  • The OLE/COM ambient property of the document is set to AMBIENT_RIGHTTOLEFT.

  • The document direction can be toggled through the document object model (DOM) (document.direction="ltr/rtl").

  • An HTML Dialog will get the correct extended windows styles set so it displays as a RTL dialog on a Bidi enabled system.

  • If the document has vertical scrollbars, they will be used on the left side if dir="rtl".

  • Although the use of the dir attribute is permitted on the body element to identify the text direction of the document, use of the dir attribute on the html element is recommended.

Description

The objective of this technique is to identify the primary text direction of a document by providing the dir attribute on the html element. The default value of dir is ltr (left-to-right), so this attribute need only be specified when the language direction is right-to-left. The dir attribute allows assistive technology to render the content of the page in its intended order.

Examples

Example 1

This example defines the text direction of the content of an HTML document to be right-to-left.

<html lang="he" dir="rtl" xmlns="http://www.w3.org/1999/xhtml">   
	<body>   
		<!-- document written in Hebrew -->  
	</body>
</html>

Resources

Tests

Procedure
  1. Examine the html element of the document.

  2. If the primary text direction of the document is right-to-left, check that the html element has a dir attribute with the value "rtl".

Expected Results
  • The above check is true.


H56: Using the dir attribute on an inline element to resolve problems with nested directional runs

Applicability

(X)HTML

This technique is referenced from:

User Agent and Assistive Technology Support Notes

Description

The objective of this technique is to identify changes in the text direction of text that includes nested directional runs by providing the dir attribute on inline elements. A nested directional run is a run of text that includes mixed directional text, for example, a paragraph in English containing a quoted Hebrew sentence which in turn includes a quotation in French. Use of the dir attribute on an enclosing span or other inline element may be necessary because the Unicode bidirectional algorithm can produce undesirable results when mixed directional text contains spaces or punctuation.

Examples

Example 1

This example defines the text direction of a mixed phrase, Hebrew and English, to be right-to-left. Because the whole quote is in Hebrew, and therefore runs right to left, the text "W3C" and the comma should appear to the left of (i.e. after) the Hebrew text.

<p>The title says "<span lang="he" dir="rtl">פעילות הבינאום, W3C</span>" in Hebrew.</p>

Resources

Tests

Procedure
  1. Examine the text direction of text in the document

  2. If the text direction is right-to-left, check that for the ancestor element that has a dir attribute, the attribute has the value "rtl"

  3. If the text direction is left-to-right, check that there is no ancestor element with a dir attribute, or that for the ancestor element that has a dir attribute, the attribute has the value "ltr"

Expected Results
  • Checks #2 and #3 are true for all text.


H57: Using the lang attribute of the html element

Applicability

(X)HTML

This technique is referenced from:

Description

The objective of this technique is to identify the primary language of a document by providing the lang attribute on the html element.

Identifying the language of the document is important for a number of reasons:

  • It allows braille translation software to substitute control codes for accented characters, and insert control codes necessary to prevent erroneous creation of Grade 2 braille contractions.

  • Speech synthesizers that support multiple languages will be able to orient and adapt to the pronunciation and syntax that are specific to the language of the page, speaking the text in the appropriate accent with proper pronunciation.

  • Marking the language can benefit future developments in technology, for example users who are unable to translate between languages themselves will be able to use machines to translate unfamiliar languages.

  • Marking the language can also assist user agents in providing definitions using a dictionary.

HTML 4.01 uses the lang attribute of the html element. XHTML served as text/html uses the lang attribute and the xml:lang attribute of the html element, in order to meet the requirements of XHTML and provide backward compatibility with HTML. XHTML served as application/xhtml+xml uses the xml:lang attribute of the html element.

(Note that HTML only offers the use of the lang attribute, while XHTML (transitionally) allows both attributes or only xml:lang , respectively, since lang was removed in XHTML 1.1.)

Examples

Example 1

This example defines the content of an HTML document to be in the French language.

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html lang="fr">   
<body>     
	...document écrit en français...   
</body>
</html>
Example 2

This example defines the content of an XHTML 1.0 document with content type of text/html to be in the French language. Both the lang and xml:lang attributes are specified in order to meet the requirements of XHTML and provide backward compatibility with HTML.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
  "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="fr" xml:lang="fr">
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
</head>
<body> 
...document écrit en français...      
</body>
</html>
						
Example 3

This example defines the content of an XHTML 1.1 document with content type of application/xhtml+xml to be in the French language. Only the xml:lang attribute is specified.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" 
   "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="fr">
<head>
	<meta http-equiv="content-type" content="application/xhtml+xml; charset=utf-8" />
</head>
<body> 
	...document écrit en français... 
</body>
</html>

Resources

Tests

Procedure
  1. Examine the html element of the document.

  2. Check that the html element has a lang attribute.

  3. Check that the value of the lang attribute conforms to RFC 3066: Tags for the identification of languages.

  4. Check that the value of the lang attribute describes the language used in most of the text of the document

Expected Results
  • The above checks are all true.


H58: Using the lang attribute to identify changes in the natural language

Applicability

(X)HTML

This technique is referenced from:

User Agent and Assistive Technology Support Notes

Description

The objective of this technique is to clearly identify any changes in language on a page by using the lang or xml:lang attribute, as appropriate for the HTML or XHTML version you use.

HTML 4.01 uses the lang attribute on elements. XHTML served as text/html uses the lang attribute and the xml:lang attribute on elements, in order to meet the requirements of XHTML and provide backward compatibility with HTML. XHTML served as application/xhtml+xml uses the xml:lang attribute on elements.

(Note that HTML only offers the use of the lang attribute, while XHTML (transitionally) allows both attributes or only xml:lang, respectively, since lang was removed in XHTML 1.1 .)

Identifying changes in language is important for a number of reasons:

  • It allows braille translation software to follow changes in language, e.g., substitute control codes for accented characters, and insert control codes necessary to prevent erroneous creation of Grade 2 braille contractions.

  • Speech synthesizers that support multiple languages will be able to speak the text in the appropriate accent with proper pronunciation. If changes are not marked, the synthesizer will try its best to speak the words in the primary language it works in. Thus, the French word for car, "voiture" would be pronounced "voyture" by a speech synthesizer that uses English as its primary language.

  • Marking changes in language can benefit future developments in technology, for example users who are unable to translate between languages themselves will be able to use machines to translate unfamiliar languages.

  • Marking changes in language can also assist user agents in providing definitions using a dictionary.

Examples

Example 1

This example uses the lang attribute of the span element to define one phrase as French and another as Italian.

<p>
And with a certain <span lang="fr">je ne sais quoi</span>, she entered both the room, and  
his life, forever. "My name is Natasha," she said.  "<span lang="it">Piacere,</span>" he  
replied in impeccable Italian, locking the door. 
</p>
Example 2

This example demonstrates the use of the xml:lang attribute defining a quote written in German. This snippet could be included by an XHTML 1.1 document where lang is not allowed.

<blockquote xml:lang="de">
<p>Da dachte der Herr daran, ihn aus dem Futter zu schaffen,
aber der Esel merkte, daß kein guter Wind wehte, lief fort
und machte sich auf den Weg nach Bremen: dort, meinte er,
könnte er ja Stadtmusikant werden.</p>
</blockquote>

Resources

Tests

Procedure

For each element in the document:

  1. Check that the natural language of the content of the element is the same as the inherited language for the element as specified in HTML 4.01, Inheritance of language codes

For each lang attribute in the document:

  1. Check that the value of the lang attribute conforms to RFC 3066 Tags for the identification of languages

Expected Results
  • All checks above are true.


H59: Using the link element and navigation tools

Applicability

HTML and XHTML

This technique is referenced from:

User Agent and Assistive Technology Support Notes

Some user agents provide an optional navigation bar which will display the information specified in the link element. Current versions of the Mozilla and Opera browsers provide this functionality. IE 6.0 and Firefox 1.5 do not offer this feature but it may be available through extensions or add-ons.

See The 'link'-Element in (X)HTML for more information on browser support for link.

Description

The objective of this technique is to describe how the link element can provide metadata about the position of an HTML page within a set of Web units or can assist in locating content with a set of Web units. The value of the rel attributes indicates what type of relation is being described, and the href attribute provides a link to the document having that relation. Multiple link elements can provide multiple relationships. Several values of rel are useful:

  • Start: Refers to the first document in a collection of documents.

  • Next: Refers to the next document in a linear sequence of documents.

  • Prev: Refers to the previous document in an ordered series of documents.

  • Contents: Refers to a document serving as a table of contents.

  • Index: Refers to a document providing an index for the current document.

Examples

Example 1

A Web unit for Chapter 2 of an on-line book might contain the following links within the head section.

<link rel="Contents" href="Contents.html" title="Table of Contents"  />
<link rel="Index" href="Index.html" title="Index" />
<link rel="Prev" href="Chapter01.html" title="01. Why Volunteer?" />
<link rel="Next" href="Chapter03.html" title="03. Who Volunteers?" />

Resources

Tests

Procedure

For a Web unit that is within a sequence or collection of Web units:

  1. Check that all link elements pertaining to navigation occur in the head section of the document.

  2. For each link element in the head section of the document which pertains to navigation, check that it contains at least:

    1. a rel attribute identifying the link type

    2. a valid href attribute to locate the appropriate resource

Expected Results
  • All of the checks above are true.


H60: Using the link element to link to a glossary

Applicability

HTML 4.x, XHTML 1.x

This technique is referenced from:

User Agent and Assistive Technology Support Notes

Some user agents provide an optional navigation bar which will display the information specified in the link element. Current versions of the Mozilla and Opera browsers provide this functionality. IE 6.0 and Firefox 1.5 do not offer this feature but it may be available through extensions or add-ons. See The 'link'-Element in (X)HTML for more information on browser support for link.

Description

The objective of this technique is to provide a mechanism for locating a glossary. When terms in the content are defined on a separate glossary page, the glossary is referenced using a link element in the head element of the document that uses the glossary. The rel attribute of the link element is set to "glossary", and the href attribute contains the URI of the glossary page. User agents can then assist users in accessing the glossary quickly and easily.

Examples

Example 1: The WCAG 2.0 Glossary.
<link rel="glossary" href="http://www.w3.org/TR/WCAG20/#glossary">

Resources

(none currently listed)

Tests

Procedure

For any set of words and their definitions that have the appearance of a list:

  1. Check that the head section of the document contains a link element

  2. Check that the link element has attribute rel="glossary"

  3. Check that the href attribute of the link element refers to the glossary page.

Expected Results
  • All checks above are true.


H62: Using the ruby element

Applicability

XHTML 1.1

This technique is referenced from:

User Agent and Assistive Technology Support Notes

Ruby markup includes a fallback mechanism for user agents that do not support XHTML 1.1.

Description

The objective of this technique is to use ruby annotation to provide information about the pronunciation and meaning of a run of text where meaning is determined by pronunciation.

There are many languages in which a run of text may mean different things depending on how the text is pronounced. This is common in East Asian languages as well as Hebrew, Arabic, and other languages; it also occurs in English and other Western European languages.

Ruby Annotation allows the author to annotate a "base text," providing a guide to pronunciation and, in some cases, a definition as well. Ruby is commonly used for text in Japanese and other East Asian languages. Ruby Annotation is defined as a module for XHTML 1.1.

There are two types of Ruby markup: simple and complex. Simple Ruby markup applies to a run of text such as a complete word or phrase. This is known as the "base" text (rb element). The Ruby annotation that indicates how to pronounce the term (the rt element, or Ruby text) is usually rendered above or immediately before the base text, and is shown in a smaller font. (The term "Ruby" is derived from a small font used for this purpose in printed texts.) A Ruby annotation that gives the meaning of the base text usually follows the base text. Simple Ruby markup also provides a "fallback" option for user agents that do not support Ruby markup (that is, user agents that do not support XHTML 1.1).

Complex Ruby markup makes it possible to divide the base text into smaller units, each of which may be associated with a separate Ruby annotation. Complex Ruby markup does not support the fallback option.

Ruby annotation is unnecessary in languages such as Hebrew, where Unicode fonts can include diacritical marks that convey pronunciation. It is also unnecessary in English and European languages.

Note: The primary reason for indicating pronunciation through Ruby or any other means is to make the content accessible to people with disabilities who could read and understand the language of the content if information about pronunciation were provided. It is not necessary to provide information about pronunciation for use by people who are not familiar with the language of the content.

Examples

Example 1: Simple ruby markup providing pronunciation information for an initialism.

This example uses Ruby annotation to give the pronunciation of the initialism (acronym) formed by the first letters of the words Web Content Accessibility Guidelines. The letters WCAG are the base (the rb element), and the pronunciation information is shown by the Ruby text (the rt element).

<p>When we talk about these guidelines, we often just call them 
<ruby>
<rb>WCAG</rb>
<rt>Wuh-KAG</rt>
</ruby>.
</p>
Example 2: Simple Ruby annotation for Japanese.

The following is an example in Japanese. For Japanese, the Ruby is used to give the reading of Han characters(Kanji).

<p>
<ruby>
<rb>慶應大学</rb>
<rt>けいおうだいがく</rt>
</ruby>
</p>
Example 3: Simple Ruby markup with parentheses for fallback

In the following example, the Ruby parenthesis element rp is used to ensure that pronunciation information shown through Ruby text is displayed by user agents that do not support Ruby annotation. The pronunciation information is rendered in parentheses immediately following the base text. (User agents that support Ruby do not show the parentheses.)

<p>When we talk about these guidelines, we often just call them 
<ruby>
<rb>WCAG</rb>
<rp>(</rp><rt>Wuh-KAG</rt><rp>)</rp>
</ruby>.
</p>
Example 4: Using the Ruby parentheses in Japanese

In the following example of Japanese text, the Ruby parenthesis element rp is used to ensure that pronunciation information shown through Ruby text is displayed by user agents that do not support Ruby annotation. The pronunciation information is rendered in parentheses immediately following the base text. (User agents that support Ruby do not show the parentheses.)

<p>
<ruby>
<rb>慶應大学</rb>
<rp>(</rp><rt>けいおうだいがく</rt><rp>)</rp>
</ruby>
</p>

Resources

Tests

Procedure

For each run of text where a Ruby annotation is used to provide pronunciation information:

  1. Check that a rt element contains pronunciation information for each run of text defined by the rb element.

  2. If simple Ruby markup is used, check that the rp element is used to provide pronunciation information for user agents that do not support Ruby annotations.

Expected Results
  • Checks #1 and #2 are true.


H63: Using the scope attribute to associate header cells and data cells in data tables

Applicability

HTML 4.01, XHTML 1.x

This technique is referenced from:

User Agent and Assistive Technology Support Notes

The scope attribute is not supported by current screen readers when there is more than one row of headers and the scope attribute is used on the first row.

Description

The objective of this technique is to associate header cells with data cells using the scope attribute. The scope attribute may be used to clarify the scope of any cell used as a header. The scope identifies whether the cell is a header for a row, column, or group of rows or columns. The values row, col, rowgroup, and colgroup identify these possible scopes respectively. For simple data tables like the one in Example 1, this technique can be used instead of the more complex technique, “ Using id and headers attributes to associate data cells with header cells in data tables."

Examples

Example 1: A simple schedule

The table below shows part of the schedule for a class. The table has four columns and three rows. The column headers are Date, Topic, What to read, and What’s due. These headers are marked with the th element, and the scope attribute is used to associate each header with its column.

The first cell in each row contains data (the date), but it also functions as a header for its row. Following the HTML 4.01 specification, it is marked as a td element because it is both a data cell and a header cell. It also has a scope attribute that associates it with its row.

<table>
…
<tr>
<th scope="col">Date</th>
<th scope="col">Topic</th>
<th scope="col">What to read</th>
<th scope="col">What’s due</th>
</tr>
<tr>
<td scope="row">September 5</td>
<td>Course overview</td>
<td>Chapter 1</td>
<td> </td>
</tr>
<tr>
<td scope="row">September 7</td>
<td>Accessibility standards</td>
<td>Introduction to WCAG 2.0</td>
<td>Written questions about Introduction</td>
<tr>
…
</table>

Resources

Tests

Procedure

For each data table:

  1. Check that all th elements have a scope attribute.

  2. Check that all td elements that act as headers for other elements have a scope attribute.

  3. Check that all scope attributes have the value row, col, rowgroup, or colgroup.

Expected Results
  • All checks above are true.


H64: Using the title attribute of the frame element

Applicability

H(X)HTML

This technique is referenced from:

User Agent and Assistive Technology Support Notes

Description

The objective of this technique is to demonstrate the use of the title attribute of the frame element to describe the contents of each frame set. This provides a label for the frame set so users can determine which frame set to enter and explore in detail. It does not label the individual page (frame) in the frame set.

Note that the title attribute labels frames, and is different from the title element which labels documents. Both should be provided, since the first facilitates navigation among frames and the second clarifies your current location.

The title attribute is not interchangeable with the name attribute. The title labels the frame for users; the name labels it for scripting and window targeting. The name is not presented to the user, only the title is.

Examples

Example 1

This example shows how to use the title attribute with frame to describe the frames containing the navigation bar and the document.

<html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <title>A simple frameset document</title>
  </head>
  <frameset cols="10%, 90%">
    <frame src="nav.html" title="Main menu" />
    <frame src="doc.html" title="Documents" />
    <noframes>
      <body>
        <a href="lib.html" title="Library link">Select to
        go to the electronic library</a>
      </body>
    </noframes>
  </frameset>
</html>

Resources

Tests

Procedure
  1. Check each frame element in the HTML source code for the presence of a title attribute.

  2. Check that the title attribute contains text that identifies the frame.

Expected Results
  • Checks #1 and #2 are true.


H65: Using the title attribute to identify form controls when the label element cannot be used

Applicability

HTML, XHTML form controls that are not identified using value, alt, or element content

This technique is referenced from:

User Agent and Assistive Technology Support Notes

  • User agents will display a tool tip when the mouse hovers above an input element containing a title attribute.

  • If no label is available, JAWS, Window-Eyes, and Home Page Reader speak the title attribute when the form control receives focus

    • JAWS 6.0 and later can be set to speak both label and title when the two items are different; however, very few users are aware of this setting.

    • WindowEyes 5.5 has a hot key, ins-E, that will display additional information, including the title attribute, for the item with focus.

    • Home Page Reader 3.04 will speak the title attribute of any element with focus when the control-shift-F1 keys are pressed simultaneously.

Description

The objective of this technique is to use the title attribute to label form controls when the visual design cannot accommodate the label (for example, if there is no text on the screen that can be identified as a label) or where it might be confusing to display a label. User agents, including assistive technology, can speak the title attribute.

Examples

Example 1: A pulldown menu that limits the scope of a search

A search form uses a pulldown menu to limit the scope of the search. The pulldown menu is immediately adjacent to the text field used to enter the search term. The relationship between the search field and the pulldown menu is clear to users who can see the visual design, which does not have room for a visible label. The title attribute is used to identify the select menu. The title attribute can be spoken by screen readers or displayed as a tool tip for people using screen magnifiers.

<label for="searchTerm">Search for:</label>
<input id="searchTerm" type="text" size="30" value="" name="searchTerm">
<select title="Search in" id="scope">
…
</select>
Example 2: Input fields for a phone number

A web page contains controls for entering a phone number in the United States, with three fields for area code, exchange, and last four digits.

<fieldset><legend>Phone number</legend>
<input id="areaCode" name="areaCode" title="Area Code" 
type="text" size="3" value="" >
<input id="exchange" name="exchange" title="First three digits of phone number" 
type="text" size="3" value="" >
<input id="lastDigits" name="lastDigits" title="Last four digits of phone number" 
type="text" size="4" value="" >
</fieldset>

Resources

Tests

Procedure
  1. Identify each form control that is not associated with a label element, either explicitly via the for attribute or by including the form control within the label element

  2. Check that the control has a title attribute

  3. Check that the title attribute identifies the purpose of the control

Expected Results
  • All checks above are true.


H67: Using null alt text and no title attribute on img elements for images that AT should ignore

Applicability

HTML 4.x and XHTML 1.x documents that load images.

This technique is referenced from:

Description

The purpose of this technique is to show how images can be marked so that they can be ignored by Assistive Technology.

If no title attribute is used, and the alt text is set to null (i.e. alt="") it indicates to assistive technology that the image can be safely ignored.

Note: Although alt=" " is also valid, alt="" is recommended.

Note: Have a "null" ALT attribute is not the same as having no ALT attribute.

Examples

Example 1

Resources

(none currently listed)

Tests

Procedure

For each image that should be ignored.

  1. Check that title attribute is either absent or empty.

  2. Check that alt attribute is present and empty or contains only whitespace (but not &nbsp;)

Expected Results
  • #1 and #2 are true


H69: Providing Heading elements at the beginning of each section of content

Applicability

HTML and XHTML

This technique is referenced from:

User Agent and Assistive Technology Support Notes

Home Page Reader, JAWS, and WindowEyes all provide navigation via headings and provide information about the level of the heading. The Opera browser provides a mechanism to navigate by headings. Additional plugins support navigation by headings in other user agents.

Description

The objective of this technique is to demonstrate how using the heading elements, h and h1 - h6, to markup the beginning of each section in the content can assist in navigation. Most assistive technologies and many user agents provide a mechanism to navigate by heading elements by providing keyboard commands that allow users to jump from one heading to the next. Using heading elements to markup sections of a document allows users to easily navigate from section to section.

Examples

Example 1

This example organizes the sections of a search page by marking each section heading using h elements.

<h1>Search Technical Periodicals</h1>
 <h2>Search</h2>
 <form action="search.php">
  <p><label for="searchInput">Enter search topic: </label>
  <input type="text" size="30" id="searchInput">
  <input type="submit" value="Go"></p>
 </form>
 <h2>Available Periodicals</h2>
 <div class="jlinks">
  <a href="pcoder.com">Professional Coder</a> |
  <a href="algo.com">Algorithms</a> |
  <a href="jse.com">Journal of Software Engineering</a>
 </div>
 <h2>Search Results</h2>
 ... search results are returned in this section ...

Resources

Tests

Procedure

For all content which is divided into separate sections,

  1. Check that each section is marked with an h element.

Expected Results
  • Check #1 is true.


H70: Using frame elements to group blocks of repeated material

Applicability

HTML, XHTML 1.0

This technique is referenced from:

User Agent and Assistive Technology Support Notes

Description

The objective of this technique is to demonstrate how framesets can be used to group blocks of repeated material. Since most user agents and assistive technology provide a way to navigate from frame to frame, using frames to organize elements can provide a mechanism for easily bypassing blocks of repeated content. If the site uses framesets, organize the blocks of content into separate frames. Make certain that the repeated blocks of content appear in the same frame within the frameset of each Web unit. In addition, each frame element must have a title attribute to describe the content of the frame. When frames are properly titled, users can use frame navigation to easily navigate between blocks of content.

Examples

Example 1

The following example shows the use of two frames to organize content. The source of the first frame is the Web unit, navigation.html, which contains the HTML for the navigation. This frame has a title attribute which identifies it as a navigation bar. The second frame contains the main content of the site as indicated by the source parameter of main.html and the title attribute, "Main News Content" which identifies its function.

 <frameset cols="20%, *">
   <frame src="navigation.html" name="navbar" title="Navigation Bar">
   <frame src="main.html" name="maincontent" title= "Main News Content" >
 </frameset>

Resources

Tests

Procedure

If the Web unit uses frames to organize content:

  1. Check if repeated blocks of content are organized into separate frames.

  2. Check that the frames with repeated content appear in the same location within each frameset.

Expected Results
  • Checks #1 and #2 are true.


H71: Providing a label for groups of radio buttons or checkboxes using the fieldset and legend elements

Applicability

HTML 4.01, XHTML 1.x

This technique is referenced from:

Description

The objective of this technique is to associate a label (such as a prompt or question) with a related group of radio buttons or checkboxes using the fieldset and legend elements. Generally, a set of radio buttons or checkboxes is related when they share the same value for the name attribute. Using fieldset and legend to associate a label with a group of form controls creates a programmatic association between the label and the group of form controls. This makes it possible for people using screen readers to hear the question or prompt as well as the available responses.

Examples

Example 1: A multiple choice test

This example shows a test item with one question and five possible answers. Each answer is represented by a radio button (input type="radio"). The radio buttons are contained within a fieldset. The test question is tagged with the legend element.

<fieldset>
<legend>The play <cite>Hamlet</cite> was written by:</legend>
<input type="radio" id="shakesp" name="hamlet" checked="checked" value="a">
<label for="shakesp">William Shakespeare</label><br />
<input type="radio" id="kipling" name="hamlet" value="b">
<label for="kipling">Rudyard Kipling</label><br />
<input type="radio" id="gbshaw" name="hamlet" value="c">
<label for="gbshaw">George Bernard Shaw</label><br />
<input type="radio" id="hem" name="hamlet" value="d">
<label for="hem">Ernest Hemingway</label><br />
<input type="radio" id="dickens" name="hamlet" value="e">
<label for="dickens">Charles Dickens</label>
</fieldset>
Example 2: A set of checkboxes

The User Profile page for a Web site allows users to indicate their interests by selecting multiple checkboxes. Each checkbox (input type="checkbox") has a label. The checkboxes are contained within a fieldset, and the legend element contains the prompt for the entire group of checkboxes.

<fieldset>
<legend>I am interested in the following (check all that apply):</legend>
<input type="checkbox" id="photo" name="interests" value="ph">
<label for="photo">Photography</label><br />
<input type="checkbox" id="watercol" name="interests" checked="checked" value="wa">
<label for="watercol">Watercolor</label><br />
<input type="checkbox" id="acrylic" name="interests" checked="checked" value="ac">
<label for="acrylic">Acrylic</label>
…
</fieldset>

Resources

Tests

Procedure
  1. Check that any group of input elements of type="radio" or type="checkbox" with the same name attribute is contained within a fieldset element

  2. Check that each fieldset has a legend element

Expected Results
  • Checks #1 and #2 are true.


H72: Using p for paragraphs

Applicability

HTML, XHTML

This technique is referenced from:

Description

The objective of this technique is to use the p element to define a coherent block of text, such as a group of related sentences that develop a single topic or a coherent part of a larger topic.

Examples

Example 1: Paragraphs describing an image of Saturn's rings

This example is taken from NASA - Sun-striped Saturn.

<p>In a dazzling and dramatic portrait painted by the Sun, the long thin shadows
 of Saturn's rings sweep across the planet's northern latitudes. Within the shadows, 
 bright bands represent areas where the ring material is less dense, while dark strips 
 and wave patterns reveal areas of denser material.</p>

<p>The shadow darkens sharply near upper right, corresponding to the boundary of the 
 thin C ring with the denser B ring. A wide-field, natural color view of these 
 shadows can be seen here. </p>

<p>The globe of Saturn's moon Mimas (398 kilometers, or 247 miles across) has wandered 
 into view near the bottom of the frame. A few of the large craters on this 
 small moon are visible.</p>

Resources

Tests

Procedure
  1. Examine the content for groups of related sentences.

  2. Check that each group of related sentences is contained within a p element.

Expected Results
  • Check #2 is true.


H73: Using the summary attribute of the table element to give an overview of data tables

Applicability

HTML 4.01, XHTML 1.x

This technique is referenced from:

Description

The objective of this technique is to provide a brief overview of how a data table is organized or a brief explanation of how to navigate the table. The summary attribute of the table element makes this information available to people who use screen readers; the information is not displayed visually.

The summary is useful when the table has a complex structure (for example, when there are several sets of row or column headers, or when there are multiple groups of columns or rows). The summary may also be helpful for simple data tables that contain many columns or rows of data.

The summary attribute may be used whether or not the table includes a caption element. If both are used, the summary should not duplicate the caption.

Use of layout tables is not recommended. However, if layout tables are used, then the summary attribute is not recommended. The purpose of a layout table is simply to control the placement of content; the table itself is “transparent" to the user. A summary would “break" this transparency by calling attention to the table. A null summary (summary="") on layout tables is acceptable.

Examples

Example 1: A data table with a summary but no caption

This example shows a bus schedule. The route number and direction are included in the summary along with information on how to use the schedule.

<table summary="Schedule for Route 7 going downtown. Service begins 
at 4:00 AM and ends at midnight. Intersections are listed in the top row. 
Find the intersection closest to your starting point or destination, then read 
down that column to find out what time the bus leaves that intersection.">
<tr>
<th scope="col">State & First</th>
<th scope="col">State & Sixth</th>
<th scope="col">State & Fifteenth</th>
<th scope="col">Fifteenth & Morrison</th>
</tr>
<td>4:00</td>
<td>4:05</td>
<td>4:11</td>
<td>4:19</td>
</tr>
…
</table>
Example 2: A data table with both a summary and a caption

In this example both a summary attribute and a caption element are used. The caption identifies the bus route. The summary helps users who are blind understand how to use the schedule. Screen readers read the caption, followed by the summary.

<table summary="Intersections are listed in row 1. 
Find the intersection closest to your starting point 
or destination, then read down that column to find 
out what time the bus leaves that intersection.  
Service begins at 4:00 AM and ends at midnight.">
<caption>Route 7 Downtown (Weekdays)</caption>
…
</table>

Resources

Tests

Procedure

For each data table:

  1. Check if a summary attribute is present for the table element.

  2. If a summary is present, check that the summary attribute describes the table's organization or explains how to use the table.

  3. Check if a caption element is present in the table element.

  4. If both a summary attribute and a caption element are present, check that the summary does not duplicate the caption.

Expected Results
  • Checks #2 and #4 are true


H74: Ensuring that all id attribute values are unique for the document AND that opening and closing tags are used according to specification

Applicability

HTML 4.01 and XHTML 1.x.

This technique is referenced from:

Description

The objective of this technique is to avoid key errors that are known to cause problems for assistive technologies when they are trying to parse content: having opening and closing tags that are not used according to specification and having duplicate id attribute values. This can be done by using HTML's mechanism to specify the technology and technology version, and making sure the Web unit does not have these types of errors in it. There are several validators that the developer can use: validation reports generally mention these two types of errors. This technique deals only with these two types of errors. The document type declaration is not strictly necessary for this type of evaluation, but specifying the document type declaration makes it easier to use a validator.

Examples

Example 1: HTML

HTML pages include a document type declaration (sometimes referred to as !DOCTYPE statement). The developer can use offline or online validators (see Resources below) to check that all id attribute values are unique and that opening and closing tags are used according to the specification.

Example 2: XHTML

Like other other XML-based documents, XHTML documents reference a Document Type Definition (DTD) or other type of XML schema. The developer can use online or offline validators (including validation tools built into editors) to check that that all id attribute values are unique and that opening and closing tags are used according to the specification.

Example 3: Using test frameworks

When a website generates XHTML dynamically instead of serving only static pages, a developer can use XHTMLUnit, XML Test Suite or a similar framework to test the generated XHTML code.

Resources

For other resources, see Validating Web units.

(none currently listed)

Tests

Procedure
  1. Check that all id attribute values are unique.

  2. Check that there are closing tags for all elements with required closing tags.

  3. Check that there are no closing tags for all elements where closing tags are forbidden.

  4. Check that opening and closing tags for all elements are correctly nested.

Expected Results

Steps 1, 2, 3 and 4 are true.


H75: Ensuring that all id attribute values are unique for the document AND that the Web unit is well-formed

Applicability

Any XML-based markup languages.

This technique is referenced from:

Description

The objective of this technique is to avoid key errors that are known to cause problems for assistive technologies when they are trying to parse content: well-formedness errors and duplicate id attribute values. Well-formedness is checked by parsing the document with a conforming XML parser. Every conforming XML parser is required to check well-formedness and stop normal processing when a well-formedness error is found (a conforming XML parser does not need to support validation). Checking that id attribute values are unique within a document can be done by validating the document against its schema, because the schema defines which attributes contain document-wide unique identifiers.

Both steps can be combined by validating the XML document and checking if the validation report mentions these two types of errors. However, if the XML document uses only the xml:id attribute as an ID attribute, validation is not necessary: parsing the XML document with a validating parser that supports the xml:id specification is sufficient.

Examples

Example 1:

XML files include a document type declaration, a xsi:schemaLocation attribute or other type of reference to a schema. The developer can use off-line or online validators, an XML editor or an IDE with XML support (see Resources below) to check well-formedness and to check that all id attribute values are unique.

Example 2:

When XML files do not include a document type declaration, a xsi:schemaLocation attribute or a processing instruction referencing a schema even though there is a schema for them, the relevant schema is specified by a command line instruction, a user dialog or a configuration file, and the XML files are checked against the schema.

Example 3:

When XML files do not include a document type declaration, a xsi:schemaLocation attribute or a processing instruction referencing a schema even though there is a schema for them, the namespace is dereferenced to retrieve a schema document or resource directory (Resource Directory Description Language: RDDL), and the XML files are checked against the schema.

Example 4:

When a website generates XML dynamically instead of serving only static documents, a developer can use XMLUnit, XML Test Suite or a similar framework to test the generated XML code.

Resources

See also Validating Web units.

(none currently listed)

Tests

Procedure
  1. Load each file into a validating XML parser.

  2. Check that all id attribute values are unique in the file.

  3. Check that there are no well-formedness errors.

Expected Results

Steps 2 and 3 are true.


H76: Using meta refresh to create an instant client-side redirect

Applicability

HTML 4.x and XHTML 1.x.

This technique is referenced from:

Description

The objective of this technique is to enable redirects on the client side without confusing the user. Redirects are preferably implemented on the server side (see Implementing automatic redirects on the server side instead of on the client side), but authors do not always have control over server-side technologies.

HTML 4.x and XHTML 1.x, one can use the meta element with the value of the http-equiv attribute set to "Refresh" and the value of the content attribute set to "0" (meaning zero seconds), followed by the URL that the browser should request. It is important that the time-out is set to zero, to avoid that content is displayed before the new page is loaded. The page containing the redirect code should only contain information related to the redirect.

Examples

Example 1
  
<html xmlns="http://www.w3.org/1999/xhtml">    
  <head>      
    <title>The Tudors</title>      
    <meta http-equiv="refresh" content="0;URL='http://thetudors.example.com/'" />    
  </head>    
  <body> 
    <p>This page has moved to a <a href="http://thetudors.example.com/">
      theTudors.example.com</a>.</p> 
  </body>  
</html> 

Resources

Tests

Procedure
  1. Find all meta elements in the document.

  2. For each meta element, check if it contains the attribute http-equiv with value "refresh" (case-insensitive) and the content attribute with a number greater than 0 followed by ;'URL=anyURL' (where anyURL stands for the URL that should replace the current page).

Expected Results

Step 2 is false.


6. Server Side Techniques


SVR1: Implementing automatic redirects on the server side instead of on the client side

Applicability

Server-side technologies, including server-side scripting languages and server configuration files with URLs or URL patterns for redirects.

This technique is referenced from:

Description

The objective of this technique is to avoid confusion that may be caused when two new pages are loaded in quick succession because one page (the one requested by the user) redirects to another. Some user agents support the use of HTML's meta element to redirect the user to another page after a specified number of seconds. This makes a page inaccessible to some users, especially users with screen readers. Server-side technologies provide methods to implement redirects in a way that does not confuse users. A server-side script or configuration file can cause the server to send an appropriate HTTP response with a status code in the 3xx range and a Location header with another URL. When the browser receives this response, the location bar changes and the browser makes a request with the new URL.

Examples

Example 1: JSP/Servlets

In Java Servlets or JavaServer Pages (JSP), developers can use HttpServletResponse.sendRedirect(String url).

…
public void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
…
  response.sendRedirect("/newUserLogin.do");
}

This sends a response with a 302 status code ("Found") and a Location header with the new URL to the user agent. It is also possible to set another status code with response.sendError(int code, String message) with one of the constants defined in the interface javax.servlet.http.HttpServletResponse as status code.

…
public void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
…
  response.sendError(response.SC_MOVED_PERMANENTLY, "/newUserLogin.do");
}

If an application uses HttpServletResponse.encodeURL(String url) for URL rewriting because the application depends on sessions, the method HttpServletResponse.encodeRedirectURL(String url) should be used instead of HttpServletResponse.sendRedirect(String url). It is also possible to rewrite a URL with HttpServletResponse.encodeURL(String url) and then pass this URL to HttpServletResponse.sendRedirect(String url).

Example 2: ASP

In Active Server Page (ASP) with VBScript, developers can use Response.Redirect.

  Response.Redirect "newUserLogin.asp"

or

Response.Redirect("newUserLogin.asp")

The code below is a more complete example with a specific HTTP status code.

Response.Clear
Response.Status = 301
Response.AddHeader "Location", "newUserLogin.asp"
Response.Flush
Response.End
Example 3: PHP

In PHP, developers can send a raw HTTP header with the header method. The code below sends a 301 status code and a new location. If the status is not explicitly set, the redirect response sends an HTTP status code 302.

 <?php
header("HTTP/1.1 301 Moved Permanently);
header("Location: http://www.example.com/newUserLogin.php");
?>
Example 4: Apache

Developers can configure the Apache Web server to handle redirects, as in the following example.

redirect 301 /oldUserLogin.jsp http://www.example.com/newUserLogin.do

Resources

(none currently listed)

Tests

Procedure
  1. Find each link or programmatic reference to another page or Web unit.

  2. For each link or programmatic reference to a URI in the set of Web units being evaluated, check if the referenced Web unit contains code (e.g. meta element or script) that causes a client-side redirect.

  3. For each link or programmatic reference to a URI in the set of Web units being evaluated, check if the referenced URI does not cause a redirect OR causes a server-side redirect without a time-out.

Expected Results
  • Step 2 is false AND step 3 is true.


7. SMIL Techniques


SM1: Providing audio descriptions in SMIL 1.0

Applicability

Applies whenever SMIL 1.0 player is available

This technique is referenced from:

Description

The objective of this technique is to provide a way for people who are blind or otherwise have trouble seeing the video in audio-visual material to be able to access the material. With this technique a description of the video is provided via audio descriptions that will fit into the gaps in the dialog in the audio-visual material.

Examples

Example 1: SMIL 1.0 audio description sample for QuickTime player
   
<?xml version="1.0" encoding="UTF-8"?>
<smil xmlns:qt="http://www.apple.com/quicktime/resources/smilextensions" 
xmlns="http://www.w3.org/TR/REC-smil" qt:time-slider="true">
  <head>
    <layout>
      <root-layout background-color="black" height="266" width="320"/>
      <region id="videoregion" background-color="black" top="26" left="0" 
      height="144" width="320"/>
    </layout>
  </head>
  <body>
    <par>
      <video dur="0:01:20.00" region="videoregion" src="salesdemo.mov" 
      alt="Sales Demo"/>
      <audio dur="0:01:20.00" src="salesdemo_ad.mp3" 
      alt="Sales Demo Audio Description"/>
    </par>
  </body>
</smil>
Example 2: SMIL 1.0 audio description sample for Realtime player
 
<?xml version="1.0" encoding="UTF-8"?>
<smil xmlns="http://www.w3.org/TR/REC-smil">
  <head>
    <layout>
      <root-layout background-color="black" height="266" width="320"/>
      <region id="videoregion" background-color="black" top="26" left="0" 
      height="144" width="320"/>
    </layout>
  </head>
  <body>
    <par>
      <video src="salesdemo.mov" region="videoregion" title="Sales Demo" 
      alt="Sales Demo"/>
      <audio src="salesdemo_ad.mp3" title="audio description" 
      alt="Sales Demo Audio Description"/>
    </par>
  </body>
</smil>

Resources

Tests

Procedure
  1. Find method for turning on audio description from content/player(unless it is always played by default)

  2. Play file with audio descriptions

  3. Check whether audio descriptions are played

Expected Results
  • #2 is true


SM2: Adding extended audio descriptions in SMIL 2.0

Applicability

Applies whenever SMIL 2.0 player is available

User Agent and Assistive Technology Support Notes

This technique is referenced from:

Description

The purpose of this technique is to allow there to be more audio description than will fit into the gaps in the dialog of the audio-visual material.

With SMIL 2.0 it is possible to specify that particular audio files be played at particular times, and that the program be frozen (paused) while the audio file is being played.

The effect is that the video appears to play through from end to end but freezes in places while a longer audio description is provided. It then continues automatically when the audio description is complete.

To turn the extended audio description on and off one could use script to switch back and forth between two SMIL scripts, one with and one without the extended audio description lines. Or script could be used to add or remove the extended audio description lines from the SMIL file so that the film clips would just play uninterrupted.

If scripting is not available then two versions of the SMIL file could be provided, one with and one without extended audio descriptions.

Examples

Example 1: Video with extended audio description.
<smil xmlns="//www.w3.org/2001/SMIL20/Language"> 
<head> 
<layout> 
<root-layout backgroundColor="black" height="266" width="320"/> 
<region id="video" backgroundColor="black" top="26" left="0" 
height="144" width="320"/> 
</layout> 
</head> 
<body>	 
<excl> 
<priorityClass peers="pause"> 
<video src="movie.rm" region="video" title="video" alt="video" /> 
<audio src="desc1.rm" begin="12.85s" alt="Description 1" /> 
<audio src="desc2.rm" begin="33.71s" alt="Description 2" /> 
<audio src="desc3.rm" begin="42.65s" alt="Description 3" /> 
<audio src="desc4.rm" begin="59.80s" alt="Description 4" /> 
</priorityClass> 
</excl> 
</body> 
     </smil> 

Resources

Tests

Procedure
  1. Play file with extended audio descriptions

  2. Check whether video freezes in places and plays extended audio description

Expected Results
  • #2 is true


SM6: Providing audio descriptions in SMIL 1.0

Applicability

Applies w