Shaping the WCAG 2.0 extensions

A few months ago, we announced an an updated charter for the Web Content Accessibility Guidelines (WCAG) Working Group that allows the group to develop extensions to WCAG 2.0. Extensions will be separate guideline documents, to increase the amount of coverage on particular accessibility needs. The group set to work right away to establish the framework for these extensions, because three task forces are already working on material intended to become extensions. To address questions of scope, conformance, and relationships among extensions, the Working Group today published Requirements for WCAG 2.0 Extensions. We seek wide review of this draft, before the requirements are finalized, to ensure that extensions will strike an appropriate balance between meeting the needs of users with disabilities, working within existing WCAG 2.0 conformance policies, and implementability.

The extension requirements have the following goals:

1. Satisfy pre-existing requirements for WCAG 2.0,
2. Ensure that web pages which conform to WCAG 2.0 plus an extension also conform to WCAG 2.0 on its own,
3. Ensure that all WCAG extensions are compatible with each other,
4. Define a clear conformance model for WCAG 2.0 plus extensions, and
5. Ensure the conformance structure utilizes the WCAG 2.0 A/AA/AAA model.

The first two requirements aim to maximize compatibility of extensions with the WCAG 2.0 base standard. This will help retain the benefits of harmonization of web accessibility practices that WCAG 2.0 has brought and help ensure that extensions can be easily applied to sites that conform to WCAG 2.0. Extensions, like WCAG 2.0, need to provide clear conformance requirements, that provide a clear accessibility benefit, are technology neutral, work on the existing and future Web, and can have their success objectively verified. Extensions can augment WCAG 2.0 success criteria, but only in a way that raises the conformance bar, not in a way that lowers it. This ensures that sites that adopt one or more extensions remain interoperable with sites that conform to WCAG 2.0 on its own.

The third requirement, that extensions are compatible with each other, was a challenge for the Working Group. If there are conflicts between extensions, sites could be unable to conform to more than one extension, thereby making the extensions less universally applicable. On the other hand, the currently anticipated extensions are designed to address specific issues that have come up, and sites may primarily adopt the extension that addresses the needs of their own audience. The current wording of the requirement is that extensions should strive to avoid conflicting requirements, working within the Working Group to address issues found, but does not completely forbid conflicts. There are considerations in favor both of allowing and of forbidding conflicts between extensions, and input on this topic from people who expect to use extensions would be especially helpful at this stage.

The final requirements address the conformance model of extensions. For sites to conform to a WCAG 2.0 extension, it must first conform to WCAG 2.0 on its own. If going further to conform to an extension, the conformance claim to that extension is at the same level (A, AA, or AAA) as the base WCAG 2.0 conformance level for the site. Extensions may or may not provide success criteria at all three conformance levels, but there will be a way to conform to WCAG 2.0 plus extensions at any given conformance level.

It is important to recognize that extensions are based on WCAG 2.0, and are not intended to radically change the landscape of accessibility guidelines. They address specific issues that now need consideration because of technology changes or emerging knowledge since the time it was finalized. Future accessibility guidelines may go beyond this to recast the guidelines in a way to better address technology evolution we now see and to better address the whole of the web accessibility picture. When this happens, some recommendations that first appear in WCAG 2.0 extensions could appear in these later guidelines, but some might not. As the extensions mature, the Working Group will turn its attention to the longer timeline and consider the shape of future guidelines.

Your input on these extension requirements is important to the ultimate success of the extensions. Please review and comment on these proposed requirements. The Working Group requests input by 5 February 2016 so it can address any issues raised and turn its focus fully onto the extensions themselves.