DISinHE: Web Content Accessibility

paul booth

DISinHE: Web Content Accessibility

Paul Booth discusses Web content accessibility.

The web is one of the most rapidly developing media for communication and information storage and retrieval available today. Many people with extra-ordinary needs (such as users of palm-tops, legacy systems, and car-based systems, as well as disabled people using special technology) are restricted from access to the information available on the web, due to poor design caused by both a lack of information and sources of good advice for developers.

Currently Higher Education in the UK is exempt from legislation protecting the rights of disabled people to equal access to information. However, pending changes to the law may remove this status, leaving many universities with potentially illegal information and courseware on their web servers. Help is at hand however: on May the 5^th of this year the World Wide Web Consortium (W3C) announced the release of its Web content accessibility guidelines recommendation, a set of definitive guidelines for web developers to ensure the accessibility of what is created.

"The Web Content Accessibility Guidelines explain what to do," said Tim Berners-Lee, Director of W3C in the organisations press release, "It has always been difficult to know, when making a site more accessible, which changes are critical. These guidelines answer that question, and set common expectations so that providers of Web sites and users can be much more strategic. The bar has been set, and technologically it is not a very high bar. Some of the items in these guidelines will be unnecessary once authoring tools do them automatically. Now it is time to see which sites can live up to this."

As a part of the Guidelines, the W3C have released checklists for web designers to review web sites. These lists clearly delineate three different levels of priority in the guidelines, based on that particular checkpoints’ impact on disability:

Priority one checkpoints must be satisfied by the developer, "Otherwise, one or more groups will find it impossible to access information in the document."
Priority two checkpoints should be satisfied by the developer or several groups of people will have difficulty in accessing the information on the page.
Priority three checkpoints may be satisfied to improve the access of the page.

The full checklist is available on-line from the W3C web site (see below).

In addition to the W3C guidelines, accessibility validation tools are also available. These tools, for example Bobby from the Centre for Applied Special Technology (CAST), validate and rate entire web sites against many of the checkpoints and issues raised by the W3C.

Checklists and site validation are extremely useful tools for developers to have. In order to prevent mistakes being made at design time, however, the consortium have also devised a QuickTips card. The aim of these is to raise awareness of the key concepts of accessible web design. The top ten key concepts of web accessibility quoted from the W3C QuickTips cards are:

Images & animations. Use the alt attribute to describe the function of all visuals.
Image maps. Use client-side MAP and text for hotspots.
Multimedia. Provide captioning and transcripts of audio, descriptions of video, and accessible versions in case inaccessible formats are used.
Hypertext links. Use text that makes sense when read out of context. For instance, do not use "click here."
Page organization. Use headings, lists, and consistent structure. Use CSS for layout and style where possible.
Graphs & charts. Summarize or use the longdesc attribute.
Scripts, applets, & plug-ins. Provide alternative content in case active features are inaccessible or unsupported.
Frames. Label with the title or name attribute.
Tables. Make line by line reading sensible. Summarize. Avoid using tables for column layout.
Check your work. Validate the HTML. Use evaluation tools and text-only browsers to verify accessibility.

For more information about Disability and Information Systems in Higher Education, please visit the DISinHE web site: http://www.disinhe.ac.uk/ The DISinHE Centre is a JISC funded project.

The Web Content Accessibility Guidelines and checklists are available from the W3C web site:

W3C Web Accessibility Initiative: http://www.w3.org/WAI/

Guidelines: http://www.w3.org/TR/WAI-WEBCONTENT/

Checklist: http://www.w3.org/TR/1999/WAI-WEBCONTENT-19990324/full-checklist.html

The Centre for Applied Special Technology (CAST)’s Bobby tool: http://www.cast.org/bobby/

W3C material quoted here is reproduced with permission and is Copyright © World Wide Web Consortium <http://www.w3.org> , (Massachusetts Institute of Technology <http://www.lcs.mit.edu/> , Institut National de Recherche en Informatique et en Automatique <http://www.inria.fr/> , Keio University <http://www.keio.ac.jp/>). All Rights Reserved. http://www.w3.org/Consortium/Legal/