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RE: Summary of arguements FOR validity -- and another against -- and a third of alternatives

From: Gregg Vanderheiden <gv@trace.wisc.edu>
Date: Sat, 5 Nov 2005 15:05:46 -0600
To: "'Gez Lemon'" <gez.lemon@gmail.com>
Cc: <w3c-wai-gl@w3.org>
Message-ID: <004501c5e24c$b3b96230$ee8cfea9@NC6000BAK>

Thanks Gez 

Anyone - any others? 

 -- ------------------------------ 
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 Gez Lemon
Sent: Friday, November 04, 2005 7:37 PM
To: Gregg Vanderheiden
Cc: w3c-wai-gl@w3.org
Subject: Re: Summary of arguements FOR validity -- and another against --
and a third of alternatives

Hi Gregg,

I've tried to be as objective as I can, but it would be helpful if people
could go through the list and ensure that I've represented their viewpoint
fairly and accurately, and ensure I haven't missed any important points -
particularly as I am biased towards requiring validity in the guidelines.

On 04/11/05, Gregg Vanderheiden <gv@trace.wisc.edu> wrote:
> 1) Can someone give me a list of the arguments FOR including validity.

* Validity errors can and sometimes do result in accessibility barriers

* Invalid documents are not testable, so it cannot be guaranteed that the
final rendering will be accurate for AT

* How can elements be programmatically determined if you can't be sure that
the content is valid

* It is doubtful, and not testable, that other guidelines catch all validity
errors that could result in an accessibility barrier

* The four principles on which WCAG 2.0 is based require valid code to be

* Specifications are designed with accessibility in mind, so there should be
no need for invalidity

* There are always ways to work around issues validly

* Invalidly addressing an issue could cause other issues

* There is a deep fundamental flaw with a set of standards that proposes to
use a baseline concept, but fully rejects embracing basic syntax checking
available with the core technologies

* Promoting robust and stable long-term standards, even if the face of known
issues - which we have every reason to believe will be temporary
- is being practical.

* Validity is a stable target - if authors follow validity guidelines, OS /
browser / plug-in / AT will all improve

* Validity has been a requirement in WCAG 1.0, and no one knows of a case
where someone has been prosecuted for invalid content

* People get prosecuted because they fail to consider others, but for having
invalid content

* Disrespectful of other specifications, including w3C specifications

* Validity offers a solid base on which to build accessibility, and
encourages accessibility to be considered from the ground up, and helps
safeguard against errors creeping in at a later stage if there is an effort
to ensure validity through the project lifecycle.

> 2) Now I need someone (else?) to send one of the arguments against.

* Additional markup may be necessary to overcome problems that the
specification authors were not aware of, and so is not part of the
specification, but could improve accessibility

* There are other level 1 success criteria that safeguard against
accessibility barriers that could be introduced with invalid markup

* Too difficult to achieve because of the tools that generate markup

* Some developers think they're being clever creating accessible content,
but they aren't (cargo cult)

* Not all validation errors are of the same level of importance to

* It is possible to have invalid markup that is accessible

* It is possible to have valid markup that is inaccessible

* The people who wrote the specification don't really want anyone to follow

* Having validity in the document means that the document will not be

* Testability is easily achievable with invalid content by running it
through an assistive device (observe reality)

* Legislation could result in people being prosecuted for invalid markup

* Even though there has never been a case of legislation against validity,
there could be in the future

* Legislators can't reasonably be expected to read a document that they're
using for legislation to determine which parts they intend to apply

* We're shooting ourselves in the head

> 3) Now if someone can summarize any alternatives or variations

I wouldn't support them all, but for completion:

* Validity at level 1

* Validity at level 2, with techniques that address validity in the
techniques for appropriate success criterion

* Watered down version of validity at level 1, with validity a requirement
at level 3

* Validity completely removed from the guidelines (with a foreword in the
document explaining the importance of validity), and address validity in the
techniques for appropriate success criterion

Best regards,


Supplement your vitamins
Received on Saturday, 5 November 2005 21:05:52 UTC

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