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COMPARING THE ROLES AND INTERRELATIONSHIPS OF THE W3C WEB ACCESSIBILITY GUIDELINES

Presenter
Matthew May
Web Accessibility Specialist
Web Accessibility Initiative, W3C
Email: mcmay@w3.org

Abstract

The World Wide Web Consortium has developed three specifications and is working on a fourth covering the creation and delivery of accessible Web content. This presentation will provide information on the latest implementation status of each of these specifications, and introduce test suites and other tools for evaluating user agents for accessibility.

Introduction

The World Wide Web has had a dramatic effect on the flow of information. The Web publishing process is remarkably different from the various tasks required to operating the old-fashioned printing press. The roles themselves, however, are no different from the old model of printing: the basis of publishing is composed of an author, a message, a publishing mechanism and a medium. While we've traded presses for Web authoring tools and paper for Web browsers, the four elements are essential to the process, and those elements are reflected in the W3C's approach to Web accessibility.

It is not only up to authors to produce content that is accessible. A true approach to Web accessibility requires harmonization of every element in the process affecting the user: the author, the authoring tool, the user agent, and the message. These four elements interact with each other in an increasing number of ways, and without guidance on how to work together, these interactions would continue to place barriers to accessibility. It is incumbent upon all members of the process, including end users, to demand a common and interoperable platform for the production and transmission of Web content. This platform is laid out in W3C/WAI's Web Content Accessibility Guidelines (WCAG), Authoring Tool Accessibility Guidelines (ATAG), User Agent Accessibility Guidelines (UAAG), and XML Accessibility Guidelines (XAG).

The Author

The WCAG 1.0 specification is in use by thousands of developers worldwide, and have been used as the basis for governmental,institutional and corporate policy worldwide. The goal of the WCAG working group is to offer practices for conveying content without losing or obscuring its meaning or utility to users with different needs.

Authors have different levels of expertise with the Web languages they use. In fact, an author may consist of one individual, or an entire team of content providers and developers. They may not understand or adhere to the semantics of HTML; some designers are satisfied simply to present the content "pixel-perfect", with visual effect as their main goal.

WCAG 1.0 was written both to outline necessary elements of HTML and address its shortcomings and common misuses. WCAG version 2, currently under development, is a list of generalized principles with which Web content can be made more accessible. It is accompanied by techniques documents for several languages, including HTML and XHTML; Cascading Style Sheets (CSS); ECMAScript (JavaScript); Scalable Vector Graphics (SVG); and the Synchronized Media Integration Language (SMIL).

The Authoring Tool

Taken alone, these are millions of people who rely on WCAG's guidance for accessibility information, but sometimes fail to overcome limitations in their own tools and publishing processes. The variation in authors' skill levels and willingness to learn new additions to Web technology (evidenced by the use of the FONT element six years after style sheets were invented) makes the case for embedding accessibility features within their development tools.

While many Web authors still develop content manually in a text editor, the trend will continue toward more sophisticated specialized tools for Web content. Authoring tools include textual and WYSIWYG (what-you-see-is-what-you-get) editors; graphics editors; content management systems; and conversion tools, including "Save to HTML" functions in word processors and other programs. The ATAG 1.0 specification reflects the needs of users and authors in the development of these tools.

Content creation as a process involves deep understanding of the needs of authors, users and Web technology. The job of the authoring tool in most cases is to streamline the process, and in doing so, these tools have the power to eliminate or minimize (or, conversely, to exacerbate or introduce) problems with creating accessible content. For example, in adding non-text content such as images, these tools should facilitate the input of conditional content.

Since the role of the authoring tool is to abstract the author from the Web language used for publishing, care must be taken to avoid generating poor-quality markup or source code. Older tools are notorious for flouting the rules and semantics of HTML in order to render visually appealing code, as well as rewriting existing code in undesirable ways. The ATAG 1.0 Recommendation requires that tools produce content that validates against the standard. This includes prepackaged content such as templates, which may be reproduced in thousands of sites. This is important for novice users who know little about accessible design by guaranteeing their content will be accessible without manipulating code. Still, more advanced users may choose to make their own accessibility enhancements at the code level, and ATAG 1.0 instructs authoring tool vendors to allow for source-level editing and retain any changes made.

Many authors have access needs of their own. One of the ATAG 1.0 guidelines makes the accessibility of the tool itself a requirement, including accessible documentation.

The User Agent

The printing press in this world is the Web browser; the broader and more flexible term is the user agent. A user agent interprets Web content and renders it readable to users: this definition includes such items as standalone search engines like Apple's Sherlock, and current and future applications of Web Services and the Semantic Web.

The fact each individual user has the ability to select how content is delivered and rendered has a dramatic impact on accessibility. The user agent is the linchpin of content delivery, responsible for translating semantics into understandable form for the user. This understandable form, however, is not cast in stone (or, where it is, it need not be). User agents are capable of flexibility on many axes, from the mode of display (e.g., visually, aurally, tactually) to capturing and catering to a user's needs and preferences.

UAAG 1.0 finally closes the loop on the accessibility of existing content. For the first time, vendors of user agents have a common reference for how to deliver conditional content to the user. UAAG goes further than the accessibility of a User Agent in its environment: the document emphasizes user control over Web content, offering users the flexibility to prevent common accessibility pitfalls, such as automatic content refreshes, which hinder many users. Also present in UAAG are techniques for repairing existing inaccessible content, designed to offer users some hints about missing content.

Web site repair aids accessibility one site at a time. Authoring tool accessibility guidance aids one group of authors at a time. But user agent accessibility -- and standardization -- has the potential to benefit authors and users alike. Thus, Web accessibility in user agents, including such details as when and how to render conditional content, must not be left to ad-hoc interpretation, and is critical to access for all.

UAAG's role is to come to some agreement on how to render and repair Web content, so that authors and users can rely on a certain set of behaviors, rather than the process of trial, error and competing implementations that affects accessibility today. To further clarify these behaviors, the working group has produced a test suite for user agents to compare their implementations against the standard.

The Message

Marshall McLuhan's trademark phrase, "the medium is the message," is amply demonstrated by the Web: the medium, the Web language that Authors use to publish content, defines and gives deeper semantic meaning to the message. The design of Web languages has profound and widespread impact on how the Web is used, searched, and understood by users.

The most effective solution for developing future accessibility is to cause the developers of future languages to think in terms of exposing content in a manner that is usable by a wide array of modalities and user scenarios. With this in mind, W3C/WAI is developing the XML Accessibility Guidelines (XAG). XML is a foundation for the creation of other languages, and most of the languages promulgated by W3C groups are XML-based, including XHTML, SMIL and SVG. The XAG document is meant to direct the developers of all XML languages in designing accessible frameworks from the beginning. This architectural standard will be adopted in the development of W3C languages in an effort to make accessible content progressively easier to produce.

Unifying Perspectives on the Web

A universal approach to accessibility helps everyone. But sites which comply with WCAG are only one facet of a grander vision of accessibility: there are millions of Web sites out there, but comparatively only hundreds to thousands of authoring tools and tens to hundreds of user agents. The work of the few Web language, user agent and authoring tool developers at this stage in the development of the Web is vital to the future of the accessible Web, as those few teams have the potential to forge a grand foundation for current and future universal access to the Web's resources.

About the Web Accessibility Initiative (WAI)

W3C's Web Accessibility Initiative addresses accessibility of the Web through five complementary activities including technology; guidelines; tools for evaluation and repair; education and outreach; and tools for research and development. Additional information on WAI is available at [1]http://www.w3.org/WAI.

About the World Wide Web Consortium (W3C)

The W3C is an international industry consortium created to lead the Web to its full potential by developing common protocols that promote its evolution and ensure its interoperability. To date, nearly 500 organizations are Members of the Consortium. For more information see [2]http://www.w3.org/.

References

Web Content Accessibility Guidelines 1.0 (W. Chisholm, G. Vanderheiden, I. Jacobs, eds.) http://www.w3.org/TR/WCAG10

Web Content Accessibility Guidelines 2.0 (B. Caldwell, W. Chisholm, J. White, G. Vanderheiden, eds.) http://www.w3.org/TR/WCAG20

Authoring Tool Accessibility Guidelines 1.0 (J. Treviranus, C. McCathieNevile, I. Jacobs, J. Richards, eds.) http://www.w3.org/TR/ATAG10

User Agent Accessibility Guidelines 1.0 (I. Jacobs, J. Gunderson, E. Hansen, eds.) http://www.w3.org/TR/UAAG10

User Agent Accessibility Guidelines Working Group Test Suites (J. Gunderson, I. Jacobs, M. May, C. Koteles, eds.) http://www.w3.org/WAI/UA/TS/

XML Accessibility Guidelines 1.0 (W. Chisholm, G. Vanderheiden, I. Jacobs, eds.) http://www.w3.org/TR/WCAG10

References

http://www.w3.org/WAI 


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