An Introduction To Accessible Web Design
This section of the site features articles published between 2002 and 2004. They remain here for reference purposes and may contain information that is out of date.
A number of groups around the world are working on increasing awareness and helping authors of accessible Web sites. These include the World Wide Web Consortium (W3C), the US Government and CAST/Watchfire. We will be looking at what each of these groups has done in more detail starting with the W3C.
Web Accessibility Initiative
Since 1999 the World Wide Web Consortium (W3C) (the organisation that creates the standards for the web) has been working on its "Web Accessibility Initiative" or WAI. The official mission of this initiative is:
The World Wide Web Consortium's (W3C) commitment to lead the Web to its full potential includes promoting a high degree of usability for people with disabilities. WAI, in coordination with organizations around the world, pursues accessibility of the Web through five primary areas of work: technology, guidelines, tools, education and outreach, and research and development.
The result of this initiative so far has been three sets of guidelines:
- Web Content Accessibility Guidelines 1.0,
- Authoring Tool Accessibility Guidelines 1.0 and
- User Agent Accessibility Guidelines 1.0.
The Web Content guidelines are designed to show Web site authors how to make their site accessible. The Authoring Tool guidelines are for people writing programs that can be used to create Web sites. The User Agent guidelines are for people who are creating Web browsers.
I will not be discussing Authoring Tool or User Agent guidelines any further as they are not the topic of this discussion and are only relevant to authors of those programs.
Web Content Accessibility Guidelines 1.0
The Web Content Accessibility Guidelines or WCAG became a W3C recommendation on the 5th of May 1999 (becoming a W3C recommendation is an extremely tough and long process).
It's purpose is to explain accessible use of Web technologies for those who create Web sites. This is achieved through 14 guidelines with a total of 60 checkpoints to be followed to make sure a site is accessible.
To accommodate the varying levels of effort people are willing to put in to making their sites accessible the checkpoints are broken down into 3 different priority levels. The specification lays out the three priority levels as follows:
- [Priority 1]
- A Web content developer must satisfy this checkpoint. Otherwise, one or more groups will find it impossible to access information in the document. Satisfying this checkpoint is a basic requirement for some groups to be able to use Web documents.
- [Priority 2]
- A Web content developer should satisfy this checkpoint. Otherwise, one or more groups will find it difficult to access information in the document. Satisfying this checkpoint will remove significant barriers to accessing Web documents.
- [Priority 3]
- A Web content developer may address this checkpoint. Otherwise, one or more groups will find it somewhat difficult to access information in the document. Satisfying this checkpoint will improve access to Web documents.
For those who take the time to produce pages that conform to any of the above priority levels there is a matching set of conformance levels:
- Level 'A'
- All Priority 1 checkpoints are satisfied.
- Level 'Double-A'
- All Priority 1 and 2 checkpoints are satisfied.
- Level 'Triple-A'
- All Priority 1, 2, and 3 checkpoints are satisfied
Pages, sites or portions of sites that conform to one of the three levels may then display a logo, linked to the appropriate W3C explanation of the claim:
For full details of the conformance logos see the W3C WCAG Conformance Logos. Alternatively, conformance can be specified through a text explanation such as:
This page conforms to W3C's "Web Content Accessibility Guidelines 1.0", available at http://www.w3.org/TR/1999/WAI-WEBCONTENT-19990505, level Double-A.
The text must specify:
- The guidelines title: "Web Content Accessibility Guidelines 1.0"
- The guidelines URI: http://www.w3.org/TR/1999/WAI-WEBCONTENT-19990505
- The conformance level satisfied: "A", "Double-A", or "Triple-A".
- The scope covered by the claim (e.g., page, site, or defined portion of a site.).
The Web Content Accessibility Guidelines were developed by the Web Content Accessibility Guidelines Working Group (WCAG WG). The following W3C pages will be useful to you if you would like to produce pages that conform to WCAG 1.0:
The US Government - Section 508
The US Government has endorsed the W3C Web Content Accessibility Guidelines by forcing all federal Web sites and sites that are under a federal contract to comply with the guidelines. More information can be obtained from Section 508.
While it is possible to read the Web Content Accessibility Guidelines and build your site to comply, wouldn't it be easier if there were a tool to test it for you? You've guessed it, there is, a product called Bobby was produced by a non-profit organisation called CAST in order to test sites to be sure they complied with the guidelines, it is also aware of the conformance levels and will tell you which level you are at (if any).
In December 2001 Bobby also began supporting Section 508, which makes it the most complete accessibility tester available. In July 2002 Bobby was purchased by a company called Watchfire, who now look after the product.
Bobby has it's own set of logos that work in much the same ways as the W3C logos:
Or for Section 508 compliance approved by Bobby:
You can use bobby in two ways. If you only want to test a few pages here and there it is available as a free on-line tool at http://bobby.watchfire.com/ and works in much the same way as the W3C HTML validator (if you've used it). You enter the URL of the document you want to check and then you receive a report of where you comply and where you don't. Because of the nature of the accessibility guidelines it is not possible to check everything through a program so you will still have to check some things yourself, Bobby tells you what to check.
If you want to check a lot of pages then the on-line tool has its limitations (you can only do a small number of checks per hour) so you would probably be best purchasing the downloadable version so that you can check as many pages as you like. At the time of this writing (November 2002) the price is $99.
A nice feature of Bobby is that for every guideline advice is readily available on how to make your document comply and why it is import for accessibility.
Over to you
That's the end of this introduction to accessible Web Design. For more information the urls given in the article should give you a good start (listed below). Have fun making your sites accessible!
The following sites were mentioned in the article (in document order):
- Policies Relating to Web Accessibility,
- World Wide Web Consortium (W3C),
- Web Content Accessibility Guidelines 1.0,
- Authoring Tool Accessibility Guidelines 1.0,
- User Agent Accessibility Guidelines 1.0,
- W3C WCAG Conformance Logos,
- Web Content Accessibility Guidelines Working Group (WCAG WG),
- The WCAG Guidelines,
- A checklist of the WCAG checkpoints,
- Techniques for following the WCAG guidelines,
- Section 508,
- Watchfire and