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RE: Validity as a technique

From: Gregg Vanderheiden <gv@trace.wisc.edu>
Date: Mon, 7 Nov 2005 09:51:08 -0600
To: "'Yvette Hoitink'" <y.p.hoitink@heritas.nl>, <w3c-wai-gl@w3.org>
Message-ID: <006001c5e3b3$11ee53d0$ee8cfea9@NC6000BAK>

I think this is good approach.

However note that we do not specify anything as necessary - just as
sufficient.   So necessary but not sufficient is not possible in the Guide
Doc (which cannot specify new requirements).

However, if validity is required to programmatically determine something
then it would already be covered.   

Several people have made this point - and it seems to indicate that validity
testing would be a very good tool to use in achieving the goal of
'programmatically determined'. 


 -- ------------------------------ 
Gregg C Vanderheiden Ph.D. 
Professor - Ind. Engr. & BioMed Engr.
Director - Trace R & D Center 
University of Wisconsin-Madison 

-----Original Message-----
From: w3c-wai-gl-request@w3.org [mailto:w3c-wai-gl-request@w3.org] On Behalf
Of Yvette Hoitink
Sent: Monday, November 07, 2005 9:43 AM
To: w3c-wai-gl@w3.org
Subject: Validity as a technique

Hello everyone,

I'm trying to find some middle ground on the topic of the requirement for
validity in WCAG. One of the many arguments for requiring validity at level
1 had to do with the fact that otherwise, some of our other requirements
wouldn't be met because you can't programmatically determine things if there
are syntax errors. That made me think: isn't validity a necessary but not
sufficient technique for some of our guidelines? 

I propose to delete the requirement for validity from our guideines and
instead list it as a necessary but not sufficient technique for all the
success criteria that require something can be 'programmatically
determined'. I think this would solve many of the problems:

* We do not require it in the normative section (the guidelines), which
prevents legal actions against websites that are accessible but do not
validate because they used an attribute that isn't defined in the specs.

* We limit our guidelines to things that clearly cause accessibility
problems when violated, which makes the document more believable. Since
validity falls into the category of 'how to do this' this is put in the

* We stimulate using other W3C standards and emphasize the importance of
validity without using WCAG as a platform for other agendas such as the
promotion of valid code. 

Any thoughts?

Yvette Hoitink
Heritas, Enschede, the Netherlands
E-mail: y.p.hoitink@heritas.nl
WWW: http://www.heritas.nl 
Received on Monday, 7 November 2005 15:51:21 UTC

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