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Re: Validity as a technique

From: Maurizio Boscarol <maurizio@usabile.it>
Date: Tue, 08 Nov 2005 14:22:28 +0100
Message-ID: <4370A694.8010507@usabile.it>
To: Ineke van der Maat <inekemaa@xs4all.nl>
CC: w3c-wai-gl@w3.org

Quality assurance is in fact the appropriate place to encourage valid 
code. But if we put validity in L1 we're saying some false statements:

1. Without validity there is no accessibility (false)
2. If page is invalid we can't check the programmatically determined 
issues (false: but even if it were true it had rather to do with "how to 
programmatically determine issues", not with what causes 
inaccessibility, that I think is the goal of guidelines; in other words, 
we're confounding causes with one of the tool to identify them; but to 
allow that tool we're changing what we consider as a cause...).
3. In real world ther may be (we can't exclude it now and in the future, 
both for xhtml and for css, due to the number of UA we include in our 
baseline) a case that we need to workaround some user agent bug by 
breaking some minor validity issue. If we put validity as mandatory for 
*basic* accessibility, we exclude that hypotetically cases from 
assessing a minimum level of accessibility. By the way, I can live with 
validity as "optimum level" of accessibility, somewhat of an ideal. Not 
as a basic one.

Sometimes it seems to me that some of you have on your mind a generic 
quality of web, not basic (L1) accessibility issues. But maybe I can't 
understand the scope of the wcag: it's possible.

Most of all, there's a logical constraint not to put validity as mandatory:

Premise: If validity is necessary, no invalid page should be accessible
Observation: there is at least one invalid page that is accessible 
(already discussed).

ergo... Premise must be false!

Should we insert a false statement? Validity and accessibility are two 
concept that in some occasion have a correlation. But they correlate 
because both are affected by some issues. And do not correlate for other 
issues. We should address the issues that affect both. For that we have 
the guidelines. The issues that can be programmatically determined, need 
to be parsed by a validator that identify that specific issues. 
Validation as a process should be advised, not (in)validity as a cause!

I surely can't understand why some of you talk about things like "it's 
the difference between mediocrity and excellence".. that has nothing to 
do with web accessibility. Accessibility barrier there are or there are 
not. And we have three level of priority to assess increasing level of 
accessibility, from basic to advanced. So I can't see why this should be 
a problem.

But of course I may be missing something. After reading the thread, I 
just can't see what. And I can't still understand what L1 is for (no one 
answered...). Maybe it's there the magic?


Ineke van der Maat wrote:

> Hello,
> i really don't know why the discussion is so difficult sbout validity 
> as level 1.
> "programmatically determined" can only be checked in validators when 
> the DTD is given, because not all DTDs contain the same tags and 
> attributes.
> I even was taught that a DTD only could  be written in code when that 
> code really validates to that DTD.
> Besides Quality Assurance http://www.w3.org/QA/Tips/Doctype and 
> Internalization also beg for DTDs for websites.. In the QA-page I can 
> find this important text that is also important for accessibility:
> "But the most important thing is that with most families of browsers, 
> a doctype declaration will make a lot of guessing unnecessary, and 
> will thus trigger a "standard" parsing mode, where the understanding 
> (and, as a result, the display) of the document is not only faster, it 
> is also consistent and free of any bad surprise that documents without 
> doctype will create."
> Putting this all altogether it seems to me very logical that a 
> validity-requirement should be in level 1.
> In the in October updated Internalization page 
> http://www.w3.org/International/ I found this text:
> The W3C Internationalization Activity has the goal of proposing and 
> coordinating any techniques, conventions, guidelines and activities 
> within the W3C and together with other organizations that allow and 
> make it easy to use W3C technology worldwide, with different 
> languages, scripts, and cultures.
> Greetings
> Ineke van der Maat
Received on Tuesday, 8 November 2005 13:09:58 UTC

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