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

From: Maurizio Boscarol <maurizio@usabile.it>
Date: Sat, 05 Nov 2005 16:22:54 +0100
Message-ID: <436CCE4E.2080807@usabile.it>
To: "Roberto Scano (IWA/HWG)" <rscano@iwa-italy.org>, paul.walsh@segalamtest.com, livio.mondini@tiuvizeta.it, w3c-wai-gl@w3.org

Roberto Scano (IWA/HWG) wrote:

>Try for eg. A page with follow elements unclosed:
>- table
>- td
>- tr
>- ul
>- blockquote
>- a
>Try also a page with:
>- scripting errors
>- numbered "id" attribute
>- non-sgml charset presented with encoding different than utf-8
>
>And finally test all these with text/html browser and with application/xhtml+xml.
>  
>

If a page isn't rendered, than it wouldn't pass any guideline... you 
don't need a specific validation guideline: the system simply doesn't 
work at all! And, according to principle 1, the content is NOT 
perceivable: failed! It's so simple. (1)

I think Paul stated a main concept: *if a validation error is important 
for accessibility, it should already be covered by another guideline!*

- i.e., if a table validation error messes up the readability of the 
data, it violates principle 3 and also guideline 1.3. That's all.

Validation is just a different topic from accessibility, sometimes 
related and sometimes not (and related doesn't mean "it's the same"!). 
We need to address only validation problems that cause problems to 
accessibility: and obviously we should do this by covering them with all 
the other guidelines.
And if, after that, we still have validation problem that aren't covered 
by other guidelines, that should mean that that problem isn't relevant 
for accessibility! This is true if the whole set of guidelines is 
appropriately done, as we all want!

Don't forget that other different topics, as user agents baseline, are 
covered outside wcag 2.0.

That said, validation can be a useful way for developers to check their 
work, but not a legal criterium to check accessibility, as we 
unfortunately have in Italy, because not every validation problem has a 
corresponding accessibility problem. We should say "use validation as an 
easy mean to help you reach a goal (accessibility), not as a goal 
itself. And anyway your aren't guaranteed that a valid page is an 
accessible one".

Bye

Maurizio
Received on Saturday, 5 November 2005 15:10:33 GMT

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