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Web Site Accessibility (Panel)

TAN Tin Wee <> (Moderator)
National University of Singapore

Mike BURKS <>
AT&T and ISOC Accessibility SIG

Yuri Rubinsky Foundation

AT&T Labs and W3C Web Accessibility Initiative

Chris HIZNY <>

José Luis PARDOS <>
Ambassador from Spain to Denmark and ISOC Board of Trustees


Introduction - Mike Burks


  • Definition of accessibility
  • Justification for accessibility
  • Overview of current techniques for producing accessible sites
  • Tools and techniques for judging Web site accessibility
  • XML as a technology for producing accessible Web sites
  • Examples of accessible sites
  • Accessibility resources

Definition of accessibility - Mike Burks

Ease of use

Web pages should be easy to use. If you have to struggle to movethrough the pages, or you get confused reading the text, or lookingat the pictures, or you cannot figure out how to do somethingon the site, it is not as accessible as it should be. If you havea disability and cannot use the site at all, it is not accessible.

Usable by all

An accessible site is usable by all that come to the site, disabledor not. It is as simple as that. The more people who can use it,the more people will be able to understand your message.

Why it is important

Web sites should be accessible to all who come to them. If partof the audience is unable to access your site they cannot understandthe message you are trying to convey.

Whom it will affect

Everyone is affected; accessible Web sites are usable by a largeraudience.

Justification for accessible Web sites

Cost benefits

  • Accessible sites are viewable and usable by a largeraudience.
  • Accessible Web sites do not require that information beprovided by alternative means.
  • Accessible Web sites equal more users per dollar spent.

Marketing considerations

  • There are 50 million people with disabilities in the UnitedStates.
  • There are 750 million people with disabilities worldwide.
  • The need for accessible Web sites is moving mainstream.

Designing for accessibility

  • Accessibility from the ground up
  • Accessible pages are well designed by definition
  • Retrofitting is time consuming

Moving to the mainstream

  • Mode-changing devices
  • Voice-controlled devices
  • Telephone and audio access to the Web

Overview of techniques and initiativesfor producing accessible Web sites - Mike Paciello

Current initiatives

  • ISOC SIG for Accessibility of the Internet to People withDisabilities
  • Web Accessibility Initiative (WAI)

Why so many Web accessibility problems?

Keyword = Design

Web access and design problems

For the blind and visually impaired

  • Web GUI, images, image maps
  • Navigation, tactile orientation, multimedia without sound
  • Tables, forms, frames

For the deaf

  • Poorly designed visual cues or auditory Web events
  • Multimedia without captioning
  • Web interfaces/appliances that are oriented toward voice I/O only

For others

  • Dyslexics have difficulty with "busy" screens or views
  • Many sites have poor color contrast
  • Several Web devices, appliances, kiosks are notaccessible to the physically challenged

Helpful design guidelines

  • Always provide alternative text for images(ALT="text").
  • Use short, functional text descriptions for imagesand text links.
  • Use ALT text for bullets, horizontal rules, orthumbnail links.
  • Consider using a text "anchor" page for tables.

First five basic guidelines

  1. Keep layouts simple and straightforward.
  2. Avoid side-by-side (columnar) presentation of text.
  3. If using graphics to provide organization or structure tothe document, attach ALT text to images that supply the same changesin context that the visual cues provide.
  4. Where following guidelines 1 to 3 would interfere withthe presentation of the information for some reason, a text-onlypage that shows the same information in an accessible format canbe used. The link to the text-only page should be one of the firstencountered on the graphics page and vice versa.
  5. Buttons that perform the same function on different pages(for example, "return to home page") should be in a consistentlocation on the page.

Additional guidelines

  • All image maps should be client side and use ALT text foreach link.
  • Provide text transcripts of audio and video events.
  • Test your pages for color contrasts (refer to the paper "People with Disabilities Can't Access the Web!"
  • Avoid using frames, or provide text alternative pages.

A few more...

  • Do not use blinking text or marquees.
  • Use relative font sizes; do not use absolute font sizes.
  • Provide e-mail versions of forms (downloadable).
  • Do not use browser-specific tags; stick with standard HTML.
  • Always test your pages with variety of browsers.

Evaluation and enhancement of accessibilityover the Web - Leonard Kasday

Tools and services: local aids

  • Authoring tools with built-in accessibility aids
  • Local versions of checking software

Possible services delivered over the Web

  • Proxy server transformers to match content to capabilitiesof accommodation equipment
  • Evaluation tools to check URLs and uploaded files
  • Lists and rings of pointers to good/poor sites
  • External databases (e.g., image description)
  • Test suites

Tools and services: meta-information

  • Provided by third party (not author or user)
  • Ratings of accessibility
    • Objective vs. subjective
    • Pass/fail vs. overall score
    • Address wide variety of needs and preferences
    • Use of ratings
  • Links to
    • Transformers
    • External databases (e.g., description)

WAI Ratings and Certification Interest Group role

  • As this is written, group is deciding on its goals.
  • Which tools? Which services?
  • Possible role for tools and services:
    • Recommendations
    • Coordination
    • Master list
    • Development

Accessibility and XML - Chris Hizny


The power of XML in addressing accessibility issues is the factthat, like its SGML precursor, XML separates data from its presentation.Within a structured authoring environment, all documents withina knowledge base should theoretically adhere to a single set ofrules. Display scripts (or style sheets) can then be used in variousways to tailor the presentation of the data to a specific audience.

Using style sheets

A catalog of distinctly different style sheets may be applied toa single set of documents -- each style sheet may address a specificaudience, taking into account whatever considerations make ordinarydata retrieval and consumption difficult.


Let us take this simple XML document fragment:

    <INFO AUTHOR="Marshall McLuhan" CONCEPT="User interfaces"     SOURCE="The Medium is the Massage"></INFO>    <SUMMARY><P>In analyzing McLuhan's claim that we walk backwards into    the future, looking back on our own past, one might extrapolate that user     interfaces generally attempt to mimic past paradigms for this reason.     Consider <PRODUCT>Adobe Photoshop</PRODUCT> and its references to     "paintbrushes" and the like, which do not exist in the online world, except     notionally. In using terms and concepts that people understand, interfaces    become easier to learn for those who have not been involved in the digital     revolution. The problem with this philosophy of interface design,    however, is that these interfaces, then, become limited by the "old"    concepts that they imitate. </P></SUMMARY>    <DETAIL><P>Consider the fact that new paradigms based on the nature of    computers themselves may be more difficult to learn, but since they rest    on the design of the PC itself, may be more powerful.</P>    <P>Benefits of struggling toward new paradigms for user interface design     include: </P>    <LIST TYPE="bullet"><LI>More powerful features, which harness computer    facilities which have no "analog" in the pre-digital world.</LI>    <LI>Forcing people to think in new ways, which may influence creativity    and bring the user "closer" to his computer</LI>

Note that unlike HTML, the above tag language (which is anapplication of the XML metalanguage) does not address style or presentation-- it merely tags information with concepts. For example, the<INFO> tag contains metadata about the document:

  • The CONCEPT attribute ties the documents to the "Userinterfaces" concept. All other documents that are also tiedto that concept now have a relationship with one another.
  • The AUTHOR attribute lists the author from whom the theoryor idea is taken, in this case the celebrated media analyst MarshallMcLuhan.
  • The SOURCE attribute lists the media from which the data came,McLuhan's seminal multimedia book The Medium Is theMessage.

The <SUMMARY> tag labels a distinct part of the documentas a sort of an abstract for the document. This may be used inindexing or in result lists that a search engine might deliver.

The <P> tag is similar to the one in HTMLin that it designates a paragraph. The difference is in how thattag will be interpreted for display. We will get to that in aminute.

The <DETAIL> tag labels a part of thedocument as low-level information, presumably expanding on thethemes in the <SUMMARY> tag.

The <LIST> tag signifies the start of thelist. The attendant TYPE attribute tells us thatthe list should be bulleted, rather than numbered. Each<LI> tag is an element within the list.

The <PRODUCT> tag signifies that allcontained text represents a specific commercial product.

In HTML, browsers are hard-coded and stupid. This is not meantas a slight on HTML, of course; rather, the two tag languages servedifferent purposes. HTML was developed as a Web standard forpublication with the intent that it be:

  • Easy to use
  • Standardized and ubiquitous
  • Similar to the word processor paradigm, which most peopleare familiar with

Like word processing documents, HTML documents are tagged with style. Thosedocuments are then interpreted for display by browsers that havetheir display algorithm hard-coded. Two browsers may, for example,display a paragraph (<P> tag) differently, depending onhow it is coded. Bullets used in lists, for example, often lookdifferent on different browsers.

In fact, it is interesting to note that both XML and HTML camefrom the same parent language, SGML.

How, then, does XML differ from HTML in terms of accessibility?Mostly, XML enables application developers to write their owntag language, determine the rules and hierarchy of that tag language,and display the data in a variety of ways. Let's return to ourXML fragment.

Presently, a style sheet language called XSL, or Extensible StylesheetLanguage, is being discussed by the W3C and has in fact been submittedfor approval as a standard. Future XML-compatiblebrowsers will utilize two distinct documents (rather than one aswith HTML) to display information. The first will be the XML document(or "instance"), and the second will be the style sheet.The browser will use the style sheet to determine how the datawill be displayed.

Consider just two of the possibilities in terms of accessibility:


For low-bandwidth connections, plain text might be the optimalform of display. High-bandwidth users may want the informationmore intricately formatted. In HTML, it might have been necessaryto produce two versions of the same document. In XML, only thestyle sheet changes, while the same document is served to bothkinds of users -- one utilizing extensive formatting (includingtables, frames, etc.) and one utilizing simple formatting.

Example: The metadata contained in the<INFO> tag might be displayed in a frame witha graphical background and emblem of some sort for thehigh-bandwidth user, while the low-bandwidth user would receivea plain-text style sheet.

Visually impaired

The size of text and type of font may be specified in style sheets.A style sheet with large, easier-to-read fonts might be deliveredfor the visually impaired user. In more difficult circumstances,a style sheet that does not use frames or tables (which screenreaders may have trouble with) might be delivered as an alternativeto a frames-based style sheet.

Example: The <SUMMARY> information might be delivered inlarge type in the visually impaired style sheet, while it mightappear as plain text in the default style sheet. Perhaps the wholedocument may be displayed by the default style sheet in a table.An alternative style sheet might be delivered that does not usetables, so that screen readers can effectively be used on thedocument.

Conducting searches using XML

In addition, the utilization of concepts in many ways can be usedto mimic the functionality of a relational database. Quicker,more efficient searching can be done in XML. Consider the commonproblem of file summaries in result lists. Summaries may be simplythe title of the file, or an algorithmically generated summary,which may be indecipherable.

By delimiting searches via concepts (e.g., "Show me all documentswith the concept of USER INTERFACES"), result listsshrink and search accuracy grows. Indeed, human-written summaries,such as the one in our above example, can be used to populateresult lists with verbose, grammatically correct, and pertinent documentsummaries.

With a well-defined XML tag language, users can find more relevantinformation much more quickly; decreasing time wasted wading throughdozens of hits. Shared XML tag languages enable standardization-- indeed, this has been done in both the academic chemistry andmathematics communities to some extent.

Flat-keyword searching (noncontextual) can never compete withconcept searching (contextual) in terms of accuracy -- however,combining both methods in a search engine can provide agood bridge between the past and the future, and accommodate usersof all backgrounds and philosophies.


XML is a fast-developing technology with great potential for producingaccessible Web sites. The use of style sheets allows the presentationof the same information in many different ways.

Moving a site toward improved accessibility- José Luis Pardos

Sí, Spain

  • Cultural accessibility
  • Changes to improve accessibility for people with disabilities
  • Roadblocks to improved accessibility

Concluding remarks - Mike Burks

Current state of accessibility

  • HTML 4.0 improvement
  • Developing technologies
  • Mainstream use of accessible techniques

Future of accessibility

  • Web expansion means more need for accessibility
  • New modes of access mean more use of accessible technology
  • Improving technology means more accessible Web sites

Resources for learning more about accessiblesites

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