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Re: WCAG Compliance

From: Christophe Strobbe <christophe.strobbe@esat.kuleuven.be>
Date: Thu, 02 Oct 2008 21:49:18 +0200
Message-Id: <>
To: w3c-wai-ig@w3.org

Hi Phill, All,

At 20:11 2/10/2008, Phill Jenkins wrote:
>A couple questions:
> > There is no certification body that checks the use of WCAG
>Do you mean, none that are authorized by the W3C or WAI?

I can't speak on behalf of W3C or WAI, but as far 
as I know, W3C nor WAI have authorised 
organizations to check whether web sites conform 
at the level claimed (i.e. through the WCAG conformance logos).
Of course, there have been studies and surveys to 
assess the level of accessibility of web sites in 
a certain country or a certain market sector, but 
the goal of these studies is not to control the 
use of WCAG conformance logos or to penalize web sites that abuse these logos.

>You gave a list of some organizations that 
>preform accessibility evaluations against their 
>own guidelines, usually based on WCAG 1.0.  So 
>how do we know if these interpretations of WCAG are any good?

In my opinion, we can't know if these 
interpretations of WCAG are any good unless the 
evaluation methodology is available (publicly or 
on request). I know of only a few methodologies that are publicly available:
* AccessiWeb (France): 
* the Unified Web Evaluation Methodology (UWEM): 
<http://www.wabcluster.org/uwem1_2/>, used by 
Euracert <http://www.euracert.org/en/>;
* Référentien Général d'Accessibilité pour les 
Administrations (RGAA): <http://rgaa.dgme.fr/> 
(incomplete because of missing sampling method for large sites);
* BIENE (in Germany): 
(incomplete because of missing sampling method for large sites).
(There are also a number of web sites with 
techniques for meeting WCAG or similar 
guidelines, but these don't constitute evaluation methodologies.)

>And how do we know if receiving a certificate 
>from one of these organizations is any good?

Bartimeus Accessibility in the Netherlands had 
its evaluation methodology audited for 
conformance to ISO/IEC 17020: "General Criteria 
for the operation of various types of bodies 
performing inspection" (see the newsletter - in 
Dutch - at 

I don't know of other organizations in this field 
that did this, so my impression is that it relies a lot on trust.

>And why do they have their own guidelines anyway?

Interpretations of WCAG have come about for several reasons, including:
* WCAG 1 was heavily based on HTML and CSS but 
the Web has evolved (hence also WCAG 2),
* some WCAG 1 criteria were seen as overly 
strict, e.g. not every HTML validation error is an accessibility problem,
* WCAG defines what conformance means, but many 
web sites are too big to check completely, so you 
need a methodology to sample a subset of pages; 
this is an area where different methodologies diverge,
* etc.

>And what data does anyone have that says self 
>evaluation is not a good as a 3rd party 
>evaluation?  Doesn't it really depend on the 
>evaluation methodology and the cost and time spent?

Yes, it depends on the evaluation methodology. 
But when an organizations that issue their own 
logos don't want their logos to be abused. As far 
as I know, W3C and WAI don't police the use of 
WCAG conformance logos. So the WCAG conformance 
logos are easier to abuse :-(  (That's just my take on it.)

> > conformance (not "compliance") logos. The WCAG conformance levels
>What's the difference? is this just semantics of 
>'conform to standards' verses 'comply with regulations'?

Yes. "Conformance" is the term used by WCAG and 
most other W3C specification that I've seen.

> > that web site owners claim for themselves are often overstated.
>is there any data published anywhere that backs this statement up?

I don't know. It's an impression that I share with some other people.

> > Sites that conform to WCAG 1.0 don't necessarily use a conformance logo.
>Anecdotally I agree, but other than the search 
>results of the 424 English sites using the logo, how do we know?
> > it is more useful to look for certificates and awards given
> > by third parties instead of through self assessment.
>How is that determined?  Opinion or has there been any studies of the sites?

Opinion; because third parties that provide 
certificates don't like abuse of their logos (see above).

> > However, it is important to bear in mind that these certificates and
> > awards can go out of date as sites evolve or get redesigned.
>Agree.  Same with quality self accessibility 
>assessments.  Process change, education & 
>training, and tools make a sustained difference in the data that I've seen.
>It sure would be useful to get more conformance 
>(or compliance) studies done and results published.

I'm sure we'll see more of these in the future.

(There is a web site about web accessibility 
surveys at 
but some important studies, like the DRC study from 2004, are missing.)

Best regards,


>Phill Jenkins
>IBM Research - Human Ability & Accessibility Center

Christophe Strobbe
K.U.Leuven - Dept. of Electrical Engineering - SCD
Research Group on Document Architectures
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Received on Thursday, 2 October 2008 19:50:04 UTC

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