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Accessible Web Design

Everyone, Everything, Connected was the slogan of the 6th WWW Conference held earlier this year in California, but how accessible is the web? In theory, since most documents on the web will be in HTML, a structured markup language, the web should be an ideal, widely accessible, information delivery medium. In practice, however, the increasingly visual nature of the web is in danger of alienating a large group of users, including the visually disabled, and as someone recently described themselves, the 'GUI blind'. These users include all those with slow Internet connections, perhaps accessing the Internet over a slow modem from home, or in one of the many third world countries with inadequate national communications networks.

The main cause of inaccessibility is poor design, but with a little thought visually pleasing pages can be designed that can also be viewed by text based browsers and understood by screen readers. Obviously not all web pages will be accessible to everyone, some by the very nature of the information they are conveying will have limited accessibility. However, it is important that accessibility should always be a concern when creating new pages.

Listed below are a few simple pointers to improving the accessibility of your web pages.

Make your documents consistent - if navigation aids are always in the same place on every page your site will be much easier to get around.

Use only standard HTML tags - HTML is a structured markup language, the tags are formatting constructs. Braille translation software relies on proper use of these tags to construct a meaningful translation. Some non-standard tags, such as BLINK and MARQUEE cannot be read by screen readers.

Use the ALT tag with images. If the image is purely decorative using Alt=" " or Alt="Null". For other images provide short, useful descriptions, for example for list bullets use Alt="*". If the image is complex, include a description nearby rather than a long ALT tag.

Where possible include text alternatives to image maps.

As it is often difficult for blind users to identify hyperlinks, many screen readers will provide a list of the links extracted from the surround text. Therefore, make your anchors meaningful - try just reading out the anchors to see how useful they are. For example:

<a href="">E-mail</a> with comments

Is more helpful than:

Click <a href="">here</a> to send us your comments.

Always provide an alternative mechanism for on-line forms, for example providing an e-mail or other contact address.

Use punctuation. Screen readers use punctuation to determine when to pause when reading the screen, so include all standard punctuation, for example, full stops at the end of list items.

Tables pose a special problem for screen readers as they read across the screen a line at a time, regardless of columns. This can render a multi-column document almost impossible to decipher. Consider providing a plain text alternative.

Avoid frames where possible, and always provide an alternative. Frames can greatly increase the difficulty in navigating through a site for many users, and screen readers working with frame capable browsers will not be able to deal with frames successfully.

Provide text transcriptions or descriptions for all audio clips.

File formats other than HTML (e.g. Adobe Acrobat) should be used only as alternatives to, rather than replacements for, HTML files.

Always test your pages using multiple viewers. If you don't have access to a range of browsers, try using Bobby. Bobby is an on-line validation service that will check your pages for compatibility with a range of browsers, and highlight any potential accessibility problems, e.g. missing ALT tags. Bobby can be found at

The Future

The World Wide Web Consortium (W3C) is committed to accessibility, stating that 'All the protocols and languages we issue as Recommendations should meet or exceed established accessibility goals. In addition, we will actively encourage the development of web software and content that is accessible to people with most disabilities'. It recently launched the International Web Accessibility Initiative 'to promote and achieve web functionality for people with disabilities'.

The drafts being considered for Cougar (code name for the next version of HTML) include several accessibility features, such as an extension for tables which would support rendering to Braille or speech, additional markup for forms which would aid screen readers, and better handling of client-side image maps for non-graphical browsers.

Despite improvements in technology and standards, the biggest single thing that will improve web accessibility will always continue to be thoughtful page design using valid HTML.


Links to pages on accessible web design

W3C disabilities developments page

Making the web Accessible for the Blind and Visually Impaired - Mike Paciello

WWW: Design for Accessibility. Ability (The Journal of the BCS Disability Group) Issue 18

Bobby (web validation service)

Sue Cunningham
SIMA Multimedia Support Officer
Computer Graphics Unit
Manchester Computing
University of Manchester
Manchester M13 9PL
Tel: +44 161 275 6095
Fax: : +44 161 275 6040