WCAG 2.0 Released: At last

After a long and sometimes tortuous process, the W3C has finally released Version 2 of the Web Content Accessibility Guidelines on December 11 2008.


Today W3C announces a new standard that will help Web designers and developers create sites that better meet the needs of users with disabilities and older users. Drawing on extensive experience and community feedback, the Web Content Accessibility Guidelines (WCAG) 2.0 improve upon W3C’s groundbreaking initial standard for accessible Web content.”

More at http://www.w3.org/2008/12/wcag20-pressrelease.html

WCAG 2 starts with 4 basic principles of Web accessibility – often referred to as the POUR principles:

  1. Perceivable – Information and user interface components must be presentable to users in ways they can perceive.This means it can’t be invisible to all of their senses.
  2. Operable – Users must be able to operate the interface and it can’t require interactions that the user can not perform.
  3. Understandable – Users must be able to understand the information as well as the operation of the user interface.
  4. Robust – Content must be robust enough that it can be interpreted reliably by a wide variety of user agents, including assistive technologies. It also means that the content should remain accessible as technologies and user agents evolve in the future.

Each principle contains a number of Guidelines and for each Guideline there are Success Criteria, which are basically testable statements. Advice about how to satisfy the Success Criteria is provided in a Techniques document. For each Success Criteria the document outlines “Sufficient Techniques” for meeting the Criteria and “Advisory Techniques”, which go beyond what is required, but provide suggestions about how to better address the guidelines. Known common failures to comply with a Success Criteria are also documented.

Unlike WCAG 1.0, WCAG 2.0 has been developed so that it can apply to current web technologies and to future web technologies irrespective of whether they are W3C technologies or have been developed outside the W3C, for example JavaScript, Flash, PDF etc.

As a result, WCAG 2.0 introduces the concept of “accessibility-supported” and the associated requirement that ” only accessibility supported ways of using technologies can be relied upon to satisfy the Success Criteria”.

The W3C does not specify how many, or which assistive technologies, such as Screen readers, must support a Web content technology like Flash in order for it to be considered “accessibility supported“

Also, there is no expectation for all uses of a web content technology to be accessible; but only those uses that are accessible can be relied upon when considering whether or not a site or application is accessible.

The W3C expect that lists will emerge over time of which technologies, and under which conditions, can be considered to be “accessibility supported”. And already there are a couple of W3C reports on accessibility support for ways of using web technologies, including this one about PDF.

It seems to me, the W3C is suggesting that when considering whether or not the use of a particular web content technology is accessibility supported you should:

  1. Look at the environment where the proposed web technology will be used. And in particular, the assistive technologies that are available to the intended users.
  2. Make sure the web content technology you are planning to use has user agents like readers and media-players that work with assistive technologies and don’t discriminate against people with disabilities in terms of availability or price.
  3. Make sure the web content technology you are planning to use is supported by commonly used assistive technologies – not just the latest version, or some new fangled thing.
  4. Make sure you use the web content technology in a way that supports accessibility – that is make the material well.

I feel WCAG 1.0 was well past its use-by-date and the new Guidelines are a significant improvement. However, I am a little worried that the notion of “accessibility supported”, and who decides whether or not some technology is sufficiently supported, will open a whole new can of worms for regulatory authorities around the world as they try to set web accessibility standards that they can enforce.

WCAG 2.0 Recommendation is at http://www.w3.org/TR/2008/REC-WCAG20-20081211/

The Techniques for WCAG 2.0 document is at http://www.w3.org/TR/WCAG20-TECHS/

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