Components of Web Accessibility: A Mini-Tutorial

[Much of the focus of Web accessibility has been on the responsibilities of Web content developers. This view misses the crucial interdependence of other components (building blocks) of Web development and interaction. @@why important]

This tutorial introduces how the different components each have a vital role in Web accessibility, and how the WAI accessibility guidelines cover the different components.

See also:
About the Components of Web Accessibility Mini-Tutorial
includes instructions for using this material, including
permission to use and keyboard access, such as:
use the A key to view all content on one Web page.

Web Content

Web content is the information in a Web page or Web application,
including text, images, forms, sounds, and such.

Getting Web Content

People ("users") use
Web browsers, media players,
assistive technologies, and other "user agents"
to get and interact with Web content.

Creating Web Content

Web content developers
use authoring tools and evaluation tools
to create Web content. (@@update images)

Components of Web Accessibility Together

Next, let's take a closer look at each component.
We'll use alternative text equivalents or "alt text" as an example of how
each component has a responsibility for Web accessibility...

Alt Text is:

<img alt="Web Accessibility Initiative logo"... />

• The alternative text equivalent or "alt text" for an image provides the same [functional] information in text as the image provides visually
  • [That is, whatever meaning the image conveys visually, the alt text should convey in text]
• Alt text is:
  • Read by screen readers and voicing browsers, which read aloud Web pages and are used by people who are blind and people who cannot read
  • Displayed in text browsers [@@and some mobile browsers???] in place of the image
  • Displayed in graphical browsers when images are not downloaded

Web Content with Alt Text

<img alt="Web Accessibility Initiative logo"... />

• Remember that Web content is the information in a Web site, including text, images, forms, sounds, and such. Web content also includes Web code, called markup
  • Alt text example: Web content has a role in providing alt text. Web content needs to include the alt text in the Web page markup

Browsers Getting Web Content

• Web browsers, media players, and other "user agents" are software that you use to get and interact with Web content
  • Alt text example: User agents need to provide the alt text to users when needed, for example, graphical browsers display the alt text when the user turns off images

Assistive Technologies Getting Web Content

• Assistive technologies (AT) are software and hardware that people with disabilities use to interact with the Web, such as screen readers, screen magnification software, alternative keyboards, and voice input software and switches for people who cannot use a keyboard or mouse
  • Alt text example: Assistive technologies need to provide the alt text to users, as needed; for example, screen readers read aloud the alt text

Users Getting Web Content

• Users' knowledge, skill, and strategies for using the Web are a component in Web accessibility
  • Alt text example: Users need to know how to get the alt text from their user agent or assistive technology, as needed

[@@Content?] Developers Creating Web Content

• Content developers include:
  • Web page authors, programmers, graphic designers, content producers, and such, including:
    • Content developers with disabilities
    • Users who contribute content to the Web
  • Alt text example: Content developers need to provide the appropriate alt text wording

Authoring Tools Creating Web Content

• Authoring tools are software or service to create and modify Web content, including:
  • Web page editors
  • Word processors and desktop publishing software that save files in Web formats
  • Multimedia [authoring|development|generation] tools
  • Content management systems (CMSs)
  • Web sites that let users add content, such as blogs, wikis, and photo-sharing sites
    
    
  • Alt text example: Authoring tools need to enable and encourage content developers to provide alt text; for example, when the content developer puts an image on a page, the authoring tool prompts for alt text

Evaluation Tools in Creating Web Content

• Evaluation tools help determine if a Web site meets accessibility guidelines, and include Web accessibility evaluation tools and markup (HTML) validators
  • Alt text example: Web accessibility evaluation tools need to check that alt text exists and help check that it is equivalent

The Web Accessibility Evaluation Tools List Search provides a comprehensive list of tools

Responsibilities for Web Accessibility

Web accessibility depends on every component fulfilling its responsibility.
How well each component supports accessibility makes a big difference...

Weak Components Cause Accessibility Barriers

• When one component has weak accessibility support, Web sites have accessibility barriers that make it difficult or impossible for people with disabilities to use them
  • Alt text example in authoring tools: When it is difficult to add alt text with an authoring tool, fewer content developers will provide alt text and then their Web content is not accessible

The Powerful Impact of High Quality Components

• On the other hand, when one component has strong accessibility support, it can greatly impact accessibility overall, and the others are likely to follow
  • Authoring tools example:
    • When authoring tools makes it easy to implement a Web accessibility feature, content developers are more likely to implement that feature in their content
      • When the accessibility feature is implemented in content, developers and users are more likely to demand that browsers and assistive technologies support it
    • Alt text example: When a content developer adds an image, the authoring tool can open a dialog box asking for alt text and providing guidance on what to put for alt text wording

Web Accessibility Defined

Question: How do you know who is suppose to do what for Web accessibility?
Answer: W3C WAI Accessibility Guidelines...

W3C WAI Accessibility Guidelines

• Authoring Tool Accessibility Guidelines (ATAG) addresses authoring tools
• Web Content Accessibility Guidelines (WCAG) addresses Web content, and is used by content developers, authoring tools, and accessibility evaluation tools
• User Agent Accessibility Guidelines (UAAG) addresses Web browsers and media players, including some aspects of assistive technologies

For More Information

• Essential Components of Web Accessibility provides more explanation of how the components need to work together for Web accessibility
• Overview of the Web Accessibility Initiative (WAI) Slides introduce Web accessibility and WAI
• The WAI home page lists Web accessibility highlights and links to myriad resources, including Introduction to Web Accessibility

Version: DRAFT $Date: 2006/09/22 03:52:23 $
Editor: Shawn Lawton Henry. Graphic artist: Michael Duffy.
Developed with the Education and Outreach Working Group (EOWG).
[Contacting WAI] Feedback welcome to wai-eo-editors@w3.org.