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Difference between revisions of "Web Accessibility Preliminary Evaluation"

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(Zoom)
(EOWG Notes on Color Contrast)
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* mention/discuss color blindness? {Andrew}
 
* mention/discuss color blindness? {Andrew}
 
* technical conflict between 'contrast' and 'luminosity' {Shadi}
 
* technical conflict between 'contrast' and 'luminosity' {Shadi}
 +
 +
Suggestion from SAZ:
 +
 +
[[
 +
Some people cannot read text if there is not sufficient contrast between the text and background, for example, light gray text on a light background. High contrast (for example, dark text on light background or bright text on dark background) is required by some people with visual impairments, including many older people who lose contrast sensitivity from ageing.
 +
[image low: gray on light; image: black on white; image: yellow on black]
 +
 +
While some people need high contrast, strong lighting (luminosity) can be glaring, distracting, and make the text difficult to read. Web browsers should allow people to change the color of text and background, and web pages need to work when people change these colors.
 +
 +
In addition, web pages should have a default minimum contrast ratio of at least 4.5:1 for normal-size text. The instructions below show you how to check contrast ratios for a web page.
 +
]]
  
 
</div>
 
</div>

Revision as of 00:18, 27 February 2013

Nav: EOWG wiki main page > Evaluation Pages
Old page on WAI website: Prelim Eval

Notes


Important Note: For this draft we have some tool-specific guidance. However, there are potential issues with vendor-neutraility and we might need to address this a different way — for example, moving tool-specific guidance to WebPlatform Docs or the WAI-Engage wiki where people can easily add other tools.

Easy Checks - A First Look at Web Accessibility

title ideas

Contents

[Thanks to #Contributors!]

Introduction

Introduction in WAI draft page

EOWG Comments on the Introduction

  • [done - changed] editor's discretion:section tools.
    First sentence:
    "Most of these checks you can do with any browser, that is, you do not need to download anything."
    Are the words in the right order in this sentence or should it be:
    "You can do most of these checks with any browser, that is, you do not need to download anything"? {Sylvie}
  • [done - this was from the wiki to HTMl conversion -- it added title to all links with the URI. I've removed them. good catch!]Clarity of links:
    It is not easy for the readers to read the links to the different tools as http text. May be the name of the tool/browser would be more useful?
    Example: Link text:
    "http://www.mozilla.org/en-US/firefox/new/".
    Or:
    "https://addons.mozilla.org/en-US/firefox/addon/web-developer/add-on."
    The link text questions seems to concern all the documents linked on this page. {Sylvie}
  • In Introduction, heading 3 "little background", third bullet about things you should know:
    Actual text: "screen readers read aloud the information in a web page. They are used by people who are blind and by some people with reading disabilities."
    During a training, someone told us that he thought a screeen reader was a person reading the content of the screen. Therefore, I suggest that for people who don't know this term one could write that screen readers are a piece of software. This would then read:
    "screen readers are programs/piece of software that read aloud the information in a web page. They are used by people who are blind and by some people with reading disabilities." {Sylvie February, 25 2013}

Page title

Page title in WAI draft page

EOWG Notes on Page Title

  • [done] the shortcut with the WAT toolbar is no direct one:
    You first have to press ctrl+alt+6, then press down arrow key once or type the first menu letter, maybe H for the English version of the toolbar? {Sylvie} [Thanks, Sylvie! I added it. {Shawn}]
  • [add to wish list for later] The text says: "The first thing screen readers say when the user goes to a different web page is the page title. Page titles are important for orientation — to help users know where they are and move between open pages."
    Would it be useful to have a sound clip of the screen reader going through page titles? Low priority, but maybe neat for people who don't know screen readers? {Shawn}
  • [done? edited to simplify] The text says: "Most browsers have a window title bar by default, except Chrome and IE versions 9 and later. In those browsers, and most others, you can see the full page title by hovering over the tab".
    Suggested text: "Many browsers have a window title bar and tabs, whereas others, such as Chrome and IE versions 9 and above, use tabs only to display the page title. For browsers with tabs only hover over the tab to view the full page title" {Vicki}.
  • [open] Suggest the alt-text on screen grabs include the browser name and version {Andrew}
    reply: I think it would add unnecessary clutter - lots of text and do people who cannot see the image care so much which browser & version? what do others think? {shawn}
  • [open] We should include FF web developer toolbar example too - 'Information' then 'View Page Information' opens a new window with the page title at the top {Andrew}
    why? the page title is shown in the window title bar so why would you need to use the develop toolbar to get it? {shawn}
  • comment {name}

Images for Page Title

  • To check page title - with IE WAT:
    <...image link here...>

Image text alternatives ("alt text")

alt text in WAI draft page

EOWG Notes on alt text

  • [done? "Some people prefer most images to have more detailed description; and others prefer much less description."] Text reads: "Some people prefer more description of more images; and others prefer less description."
    Suggested simplified wording: "Some people prefer more descriptive text, others prefer less". or "Some people prefer more description of images, others prefer less." I would remove the "more" of "more images" {Vicki}
    The issue is that for a given image, some people think there should be no alt at all, some think there should be brief alt, and some think there should be detailed alt. I think your re-wording misses that some people want some images to have no description at all, whereas others think those images should have some description. I tried another edit in between. :-) {shawn}
  • [done, with slight tweak.] Last paragraph. Text reads: (So "alt tag" is technically incorrect; it's "alt attribute", or you can say "alt text".)
    Minor editorial comment. Suggested text: (So "alt tag" is technically incorrect; "alt attribute" would be the correct term or you can say "alt text".) {Vicki}
  • [done] Editorial plus typo comment: Text reads: "The first one is easiest of you have the WAT toolbar." Corrected text: "The first one is the easiest if you have the WAT toolbar.". {Vicki}
  • [done] First check, point 2.: Guidance indicating color "...on a tan background." I think this might depend on the browser version and also the resolution. My version, for example, shows a pinkish background. Perhaps, you could say "... on a colored background". {Vicki}
  • [done] First check, point 4.: Editorial."... Tips below." The Tips are above. {Vicki}
  • [open EOWG] Finally, I'm mulling over the term "inappropriate alt text". Would that be the correct term? {Vicki}
    other ideas?
  • comment {name}

Keyboard Access {Andrew}

[done - add to WAI draft page 20 Feb {Shawn}]

  • To check alt text - with IE WAT {Andrew}
    • ctrl-alt-4, then arrow down to 'show images' which displays the alt-text adjacent to the image
  • To check alt text - with FF toolbar
    • Alt + 'T' for "Tools", then 'W' for "Web Developer Extension", then 'I' "Images", then 'O' for "Outline Images", then 'A' for "Outline Images Without Alt Attributes"
    • Alt + 'T' for "Tools", then 'W' for "Web Developer Extension", then 'I' "Images", then 'A' for "Display Alt Attributes"

Headings

Headings in WAI draft page

EOWG Notes on Headings

  • [done] heading h4: "To try checking headings in BAD"
    There seems to be one or two words too much:
    "Follow the one of the instructions under "To check headings outline" above"
    Suggestion:
    "Follow one of the instructions under "To check headings outline" above" {Sylvie}
  • comment {name}


Keyboard access {Andrew}:

[done - add to WAI draft page 20 Feb {Shawn}]

  • To check headings outline - with IE WAT
    • Ctrl + 6, then down arrow to "Heading Structure"
  • To check headings outline - with FF toolbar
    • Alt + T, then 'W' for "Web Developer Extension", then 'I' for "Information", then 'm' for "View Document Outline"
  • To show heading markup in the page - with IE WAT
    • Ctrl + 6, then down arrow to "Headings"
  • To show heading markup in the page - with FF toolbar
    • Alt + T for "Tools", then 'W' for "Web Developer Extension", then 'O' for "Outline", then 'S' for "Show Element Tags Names When Outlining"
    • Alt + T for "Tools", then 'W' for "Web Developer Extension", then 'O' for "Outline", then 'H' for "Outline Headings"

Color contrast

Some people cannot read text if there is not sufficient contrast between the text and background, for example, light gray text on a light background. High contrast (for example, dark text on light background or bright text on dark background) is required by some people with visual impairments, including many older people who lose contrast sensitivity from ageing.
[image low: gray on light; image: black on white; image: yellow on black]

While some people need high contrast, other people need low contrast, including people with some types of reading disabilities such as dyslexia. Web browsers should allow people to change the color of text and background, and web pages need to work when people change colors.

Web pages should also have a minimum contrast by default: a contrast ratio of at least 4.5:1 for normal-size text. The instructions below show you how to check contrast ratios for a web page.

(There is much more to know about color contrast; we've just introduced the basics here.)

[+] To check contrast with IE WAT

There are three applications within the Web Accessibility Toolbar(WAT) for IE that can be used to check for sufficient contrast. Explore these techniques to find the one that works best for your circumstance.

  1. A numerical display of contrast ratio is produced in a table format by using the WAT. Choose: Color > Juicy Studios Luminosity Analyser.
    1. Pro Quick, easy, comprehensive

    2. Con Can be inaccurate (ie, strong chance of excessive numbers of false failures)
  2. A precise measurement of contrast ratio can be made for specific instances within a page. Choose: Color > Contrast Analyser (application). The application is an eyedropper mechanism. Choose a sample from both the foreground color and background color. The application will return a Pass/Fail status along with the contrast ratio.
    1. Pro Quick, easy, accurate
    2. Con Can only test one item at a time, must have sight and the ability to use a mouse
  3. Examine the page with all color removed: In the toolbar, choose Color > Grey Scale
    1. ProQuick, easy, direct experience
    2. Con Relies on judgement, does not return numeric value of contrast ratio

[+] To check contrast with any browser

Download the Color Contrast Analyzer

Follow the previous directions for using the eyedropper tool.

[+] To practice checking contrast with BAD

With one of the checks above, use the inaccessible Tickets page: www.w3.org/WAI/demos/bad/before/tickets.html
Notice:

  • The text in some rows is dark gray on light gray with a contrast ratio of 3.76:1.

Learn more about color contrast

  • Contrast (minimum) - Understanding Success Criteria 1.4.3 for WCAG 2.0 (Level AA)
  • [@@ not include this 'cause it just adds complexity?] Contrast (enhanced) - Understanding Success Criteria 1.4.6 for WCAG 2.0 (Level AAA)



EOWG Notes on Color Contrast

  • mention/discuss color blindness? {Andrew}
  • technical conflict between 'contrast' and 'luminosity' {Shadi}

Suggestion from SAZ:

[[ Some people cannot read text if there is not sufficient contrast between the text and background, for example, light gray text on a light background. High contrast (for example, dark text on light background or bright text on dark background) is required by some people with visual impairments, including many older people who lose contrast sensitivity from ageing. [image low: gray on light; image: black on white; image: yellow on black]

While some people need high contrast, strong lighting (luminosity) can be glaring, distracting, and make the text difficult to read. Web browsers should allow people to change the color of text and background, and web pages need to work when people change these colors.

In addition, web pages should have a default minimum contrast ratio of at least 4.5:1 for normal-size text. The instructions below show you how to check contrast ratios for a web page. ]]


back to Contents

Zoom

Some people need to enlarge web content in order to read it. Enlargement is generally provided by browser functionality, and the web page needs to be designed to work when zoomed.

All major browsers provide zoom functionality that zooms all of the page, including text, images, and buttons. Additionally, most browsers provide functionality to zoom only the text. [zoom page, zoom text only]

When pages aren't designed well, sometimes columns and sections overlap, the space between lines disappears, or lines of text become too long. Some people with disabilities cannot read text that requires horizontal scrolling.

[@@ image]

To check zoom page

In most browsers:

  • From the menubar, select View > Zoom > 200%
  • Or, you can incrementally increase zoom by:
    • In Windows, press Ctrl+ (that is the control key and the + key at the same time)
    • On Mac, press Command+ (that is the ? key and the + key at the same time)

To check zoom text only

(Available in Firefox and Safari.)

In most browsers:

  • From the menubar, select View > Zoom Text Only
    or, select View > Zoom > Zoom Text Only
  • ...

@@ IE 8 text resize.

What to check for

For both page zoom and zoom text only, check the following.

  • With text resize: all text gets bigger, including in any navigation, ads, etc. [@@ Except text in images - how to explain that?]
  • With zoom: all elements on the page increase in size.
  • Text doesn't disappear or get cut off.
  • Text, images, and other content doesn't overlap.
  • All controls are clickable. [not hidden off page where you can't get to them]
  • Best practice requires that when users zoom, they do not have to scroll horizontally to read lines of text. (It is acceptable to need to scroll to get to different areas of the page.)

[+] To practice checking text size with BAD:

@@ is there a page that breaks with IE Text Size > Largest?

To learn more about zoom and text size


EOWG notes on zoom and enlarge

  • comment {name}




back to contents

Keyboard access, content order, visual focus

EOWG notes - importance: HIGH.
5min: maybe.
15min: yes, at least part of it.
Without visual rendering: @@

Many people do not use the mouse and rely on the keyboard to interact with the Web. While screen reader users rely on the keyboard, they are not the only ones. In addition, sighted users with mobility impairments may rely on the keyboard or have assistive technologies that are controlled through keyboard actions. Without using a mouse, a user must be able to make visible, logical progress through the page elements, including link activation, form inputs, media controls, and other user interface components.

What To Do

In browsers with full support of keyboard navigation, including Firefox, Chrome,IE, and Safari do the following:

  • Click in the address bar, then put your mouse aside and don't use it.
  • Press the 'tab' key to move through the interactive elements on the page.
  • For subsequent movement within elements, such as select boxes or menu bars, press the arrow keys
  • To select a specific item within an element, press the Enter key or Space bar.

What To Look For

  • Can you tab to all the elements, including links, form fields, buttons, and media player controls? Are there any actions you can't get to (e.g., if they are only available on mouse hover or click)?
  • Does the tab order follow the logical reading order, top to bottom, left to right in sequence?
  • Watch as you tab through the elements to verify that the focus indicator is clearly visible - that you can visually determine where the focus has currently landed. (Note that common failures occur when the default focus indicator is turned off in CSS or when the element is styled with borders that occlude the focus indicator.)
  • Verify that any visual changes that occur with mouse hover also are triggered with keyboard focus
  • Can you tab away from all elements that you can tab to and continue tabbing through to the end of the page, circling back again to the top? (e.g. you don't get stuck anywhere and can't move on - known as a "keyboard trap")
  • If there is a drop-down list (for example, for choosing from a select box or navigation to another menu-listed page)
    • When tabbing into the drop-down box, can you use the down/up arrow keys to move through the options?
    • When the listed content receives focus, are items indicated but not selected automatically? Selection should occur only when user signifies choice through additional keyboard action (usually Enter or Space bar)

References


back to contents


Multimedia (video, audio) alternatives

[Updated 26 February]

Check multimedia elements to ensure that visual and audio content includes equivalent alternatives and that the media player is fully accessible.

What to do

These steps will give you a quick and easy first look. They will identify that alternatives for media content have been considered and attempted. A more comprehensive testing process will be needed to verify the quality of the alternatives provided.

  1. Ensure that media does not begin to play automatically or, if it does, that it stops after 3 seconds.
  2. Follow the steps for keyboard access to ensure that the media player controls are labeled and operable by all users.
  3. Play a short piece of the audio content
  4. Play a short segment of the video content

What to look for

Captions

  • Toggle closed captions on (if available). Examine the media player controls for the closed caption icon button. @@include logo image
    • Are captions provided?
    • Do captions seem in sync with the spoken content?
    • Are the people who are speaking identified when they speak?
    • Has important audio content other than dialogue been included? (music, door slamming, applause, noises that impact meaning of narrative, etc)

Transcript

  • If no captions are provided, check page for embedded transcript or a link to a transcript page. Transcript should contain all dialogue and other meaningful audio content as well as a full description of visual content to the extent it is needed for understanding (read the following section about audio description for more information).

Audio Description

Audio description is a method of using the natural pauses in dialogue or between critical sound elements to insert narrative that describes visual image information, thereby making it accessible to blind members of an audience. On the web, audio description may be provided using a separate audio track or by means of a text description (transcript).

  • Toggle audio description on (if available). Examine the media player controls for the audio description icon button. @@include logo image
    • Is an audio description track provided in the media itself?
    • If not, is audio description provided as text?

Learn more about providing alternatives for media content



EOWG Notes on Multimedia



back to contents

Forms, form labels, and error messages

[15: maybe not]

EOWG notes.
5min: no, too complicated.
15min: not sure

Forms are used for interacting with websites and are common across the Web. They are used for activities such as search, login, registration, contact, booking and purchasing. Forms are made up of controls such as text entry fields, check boxes, radio buttons, drop-down boxes and submit buttons.

Forms need to be clear, easy to understand, an logical. Even simple forms, such as log-in and search boxes, can be problematic. Basic things to look for are:

  • instructions
  • labels
  • keyboard access
  • reading order
  • error messages

What to do

Check through the web pages to look for examples of forms.

Instructions

For longer forms, instructions are usually needed to explain how to fill out the form. For example, an explanation of mandatory fields, time-limits associated with the form, or any other information necessary to complete the form. If relevant:

  • Are there instructions at appropriate places in the form (usually at the beginning) that clearly explain how to to fill out the form?
  • Are mandatory fields explained in the instructions and clearly identified throughout the form?


[@@ move to lower down: Are there text labels (before/after?) the input fields that describe what to do and if any elements are essential]

Labels

@@ reworked to here -->

Start by reviewing the previous 'keyboard access' section to ensure that visible, logical access to form inputs is provided for those who don't use a mouse. Also review 'text alternatives' checks to ensure proper identification of any graphic buttons or other inputs.

Some critical elements that can affect screen reader users are much easier to detect using an automatic tool to check the HTML and CSS, or within a user trial with an experienced screen reader user.

Template:Forms are complex and will likely require more in-depth assessment. In the meantime, these easy visual checks will help you identify some common problems.

Are there any forms

Check through the web pages to look for examples of forms.

What to look for:

  • Forms include registration forms, contact forms, booking and purchase details which include text entry fields, radio buttons, dropdown boxes and submit buttons and also single text entry boxes such as login or search box.


Form labels

Use your mouse to check for labels explicitly tied to the form fields by clicking on the label - look to see if the cursor now appears in the associated text entry box or if the associated radio-button or check-box becomes selected.

You can also use a browser based testing tool to check the code for labels, the most reliable method for the provision of accessible forms.

What to look for:

  • In FF Toolbar > Navigation > Forms.
    [Keyboard - Alt + 'T' for "Tools", then 'W' for "Web Developer Extension", then 'F' for Forms, then 'O' for Outline Form Fields Without Labels]
    • Verify that each form has a unique associated label
  • In IE/WAT > Structure > FieldSet/Labels
    [Keyboard - Ctrl + Alt + 6 for "Structure", then arrow down to "FieldSet/Labels" and select]
    • Verify that form has a unique associated label

If forms are not provided in this conventional way, mark the form for further testing in the next, more comprehensive round.

Keyboard access and reading order

Use the Tab key and arrow keys to move through form controls, text boxes, radio buttons, drop down box and submit button. (Use shift tab to go back). Use the cursor (arrow) keys to access selection box or drop-down menu content.

What to look for:

  • Compare the sequence of information presented visually with the tab through order.
  • Follow instructions to check for equivalent Keyboard Access in previous section.

Data input and error messages

Enter correct and incorrect data – eg incorrectly formatted telephone numbers and email addresses.

What to look for: When erroneous data is entered and form submitted:

  • Ensure that error message is clear and specific about the nature of the error and the field in which it was made
  • Ensure that focus moves to the error message
  • Ensure that guidance is provided to help user understand and fix the error.

References

Several Accessibility Principles are relevant to the accessibility of forms, including those reviewed in the checks for Keyboard Access and Text alternatives. Also consider these:

  • Labels for form controls, input, and other user interface components must be provided. (Labels and Instructions 3.3.2 A)
  • Error correction: Forms may be confusing or difficult to use for many people, and, as a result, they may need more time and be more likely to make mistakes. Clear recovery mechanisms must be provided. (Error identification 3.3.1 A, Error suggestion 3.3.3.AA, Error prevention (legal, financial, data) 3.3.4 AA. Timing 2.2.1 A)
WAI's Before and After Demo (BAD)includes examples of forms that have been made accessible:

Next Steps

So, you've spent a little time getting a sense of the accessibility issues that need to be addressed, but what do you do next? How can you flag what you've discovered, while being sure that the information reaches those who can make the changes happen?

If you're a site visitor who doesn't work for the organization but wants to report accessibility-related concerns, you will likely want to reach out by using the site's contact form or by sending email to a "Webmaster" address. Of course, if you have a specific point of contact in the organization, starting with that person can be beneificial.

On the other hand, if you work for the organization that operates the site you've looked at, you might use a bug-tracking/helpdesk system to report your findings. Or you might decide it would be more effective to write a report in which you group problems and possible solutions in a way that makes sense within the company's structure.

Whether or not you work for the company that runs the site you've checked, you'll want to describe the issues clearly, including identifying the browser and any other tools you used. Providing as much detail as you can will help others replicate the issue and identify approaches to resolve it. For examples of recommendations we have developed to guide site visitors who experience difficulty accessing a web site, see a section of [ http://www.w3.org/WAI/users/inaccessible Contacting Organizations about Inaccessible Websites] called "Describe the Problem." These Sources for More Information will help your colleagues familiarize themselves with additional references for more details about problems and solutions.   When it's time to conduct a more thorough evaluation,either internally or by hiring a qualified contractor, the [WCAG-EM Evaluation Methodology Overview] (coming soon) and accompanying documents will help you or others develop plans as we all work together to provide a more accessible web for all.

EOWG Notes on Next Steps

  • comment {name}



Contributors

Thanks to:

  • Those who edited in December and January: Suzette (forms, @@), Sharron (Intro, @@), Shawn (Intro, page titles, headings, alt text), Ian (zoom n text resize).
  • Those who commented in December and January: Sylvie, Wayne, Anna Belle, ...
  • Those who drafted checks 16-28 November:
    • Sharron for drafting {list sections!}
    • Suzette for drafting : Check usable with page zoomed and text enlarged, Check color contrast, Check color coding and shape coding, {?other sections}
    • Wayne for drafting {list sections!}
  • Andrew & Shawn for editing the keyboard access & visual focus section in early Nov.
  • Ian, Suzette, Vicki, Sylvie, Helle, Shawn for working on an early draft at the f2f in Nov.
  • Sharron for help making all the early drafts and versions less confusing.
  • Wayne and Ian for sharing colleagues' related work.
  • Denis for edits to the old page content.

testing image: search-icon.png



Important Note: For this draft we have some tool-specific guidance. However, there are potential issues with vendor-neutraility and we might need to address this a different way — for example, moving tool-specific guidance to WebPlatform Docs or the WAI-Engage wiki where people can easily add other tools.