Understanding Universal Web Accessibility Bebo White SLAC
[email protected] 27 Sept 2002
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What Does Accessibility Mean? "The power of the Web is in its
universality. Access by everyone regardless of disability is an
essential aspect. -- Tim Berners-Lee W3C Director Inventor of the
World Wide Web
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Who Are the Disabled? An estimated 20% of Americans have some
form of disability (Microsoft Web site) Global statistics are
probably similar Not just the obvious Blind, deaf, severe motor
disabilities But more commonly Color deficiency, reading disorders,
aging
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The ADA and Section 508 In 1998, the U.S. Congress amended the
Rehabilitation Act to require Federal agencies to make their
electronic and information technology accessible to people with
disabilities Inaccessible technology interferes with an
individual's ability to obtain and use information quickly and
easily Disabled employees must have access to information
comparable to others
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The ADA and Section 508 (cont) Section 508 was enacted to
eliminate barriers in information technology to make available new
opportunities for people with disabilities to encourage development
of technologies that will help achieve these goals Applies to, but
is not limited to, computers, ancillary equipment, software,
telecommunication products, information kiosks, Web sites,
multimedia, and office equipment
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Web Content Accessibility Guidelines (WCAG) Published by the
W3C Now at Version 1.0 http://www.w3.org/TR/WAI- WEBCONTENT
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General WCAG 1.0 Principles Provide a text equivalent for every
non- text element (e.g., via "alt", "longdesc", or in element
content). Ensure that all information conveyed with color is also
available without color, for example from context or markup.
Clearly identify changes in the natural language of a document's
text and any text equivalents (e.g., captions).
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General WCAG 1.0 Principles Organize documents so they may be
read without style sheets. Ensure that equivalents for dynamic
content are updated when the dynamic content changes. Until user
agents allow users to control flickering, avoid causing the screen
to flicker. Use the clearest and simplest language appropriate for
a site's content.
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Accessibility Tools Bobby - http://bobby.watchfire.com/bobby/ht
ml/en/index.jsp http://www.w3.org/WAI/ER/ existingtools.html
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Bobby and the HKU Site
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Universal Accessibility Anyone or anything using any kind of
Web client technology on any Web-enabled platform should be able to
visit any site and get a full and complete understanding of the
information contained therein as well as have the full and complete
ability to interact with that site as necessary
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Internet Web Server
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Benefits of Universal Accessibility Increase market share and
audience reach Improve usability for non-disabled and disabled
visitors Support for low literacy levels Improve search engine
listings and resource discovery Support for the Semantic Web
Repurpose content for multiple formats or devices Increase support
for internationalization Assisting access for low-bandwidth
users
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Benefits of Universal Accessibility (2) Improve efficiency
Reduce site maintenance Site search engine improvements Repurposing
content Address server-load Address server-bandwidth Demonstrate
social responsibility Reduce legal liability
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Market Share Benefits of Accessible Web Site Design (from
Andrew Arch and Chuck LeTourneau)
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Technical Efficiency Benefits of Accessible Web Site Design
(from Andrew Arch and Chuck LeTourneau)
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The Key to Universal Accessibility is Repurposing Content is
what you say Presentation is how you present it Content is
invariant Presentation is variable Repurposing is matching content
to presentation Tools for repurposing are available now
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Complex System Meta-layer of all communication between user and
system Use Profiles (e.g., CSS, XSL, XHTML, XML) Interface 1
Interface 2 Interface 3 User 1 User 2 User 3 Interface Generator
Content Presentation (e.g., RDF)
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Accessible design is not only good design, its good sense!
