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Re: A UK user survey an accessibility/usability

From: Maurizio Boscarol <maurizio@usabile.it>
Date: Wed, 09 Nov 2005 16:14:28 +0100
Message-ID: <43721254.4010608@usabile.it>
To: Gez Lemon <gez.lemon@gmail.com>
CC: W3C WAI <w3c-wai-gl@w3.org>

Gez Lemon wrote:

>On 09/11/05, Maurizio Boscarol <maurizio@usabile.it> wrote:
>>Just to point to your attention this survey (*):
>>There's much to say about methodology (a survey isn't a user testing),
>>but it's meaningful that people need ease of use. Rarely mentioned
>>tech-related issues, often organization, clarity, language and
>>perceptual issues.
>The reason tech related issues do not appear is because they're
>questions that were asked of end users. As one of the arguments
>against validity is that web developers don't understand validity, it
>seems a bit unreasonable to ask an end user to rank the importance of
>validity. As far as they're concerned, they can either access the
>content or they can't.

Exactly. But even with invalid pages they don't have technical problem 
accessing the pages. So validity *may* be an issue in certain cases, but 
it's not a necessary requirement for end user to have basic accessibility!

It's not reasonable to assume that the 208 users visited only valid 
pages. Most of the web is invalid. The users could anyway access and use 
them. And the problem they report don't seem reasonably directly related 
to validity problems (this can only be inferred).

The problem now is: do we need to admit this simple evidence, or are we 
making an "ideal" set of guidelines that assess only higher and ideal 
level of accessibility excluding the possibility that, at least at a 
minimum level, even some invalid page could not have accessibility problem?

>This reminds me of a usability study performed by Egg, where they had
>an image of a credit card containing the typical APR. The alternative
>text for the image was "Credit Card", and the typical APR wasn't
>mentioned anywhere else on the page. They ran usability tests, and
>included people with no vision using screen readers who gave them the
>all clear that the page was understandable. 

Sorry, but this point isn't pro validity. The problem here is the 
meaningfulness of the alt text, that can't be programmatically determined.

>Usability tests and surveys are only as good as the questions asked.

Well, but if validity were "preliminar", every invalid page couldn't be 
succesfully used. And this is proven to be untrue.
I hope you see that the problem isn't validity itself, which I agree to 
at a certain quality level. The problem for me is if we had to exclude 
the possibility of invalid pages to be considered accessible (at least 
at basic level) by the wcag 2.0.

Well, if you only need a standard to force UA/AT productors, well, that 
standards are the DTD and UAG/ATAG. I thought we should address real 
accessibility problems, from the most basic to the more rare and 
advanced (even ideal, but at higher level).

>Validity isn't the sort of thing you could ask an end-user to rank in
>terms of importance, so the results of a survey aimed at end users
>isn't the best place to seek advice as to whether or not validity is

I agree. But if a user says "the data table were messed up", or similar 
issues, we could infere that they are validity related...

>We can continue to search for extreme edge cases

Extreme edge cases?? 208 disabled user in real navigation cases and no 
mention to issues that we could infer be related to validity maybe is 
not decisive, but is definitely not an edge case!

> but ultimately, validity does
>play an important part in ensuring that content is accessible. If
>content isn't valid, then it can't be guaranteed that it could be
>correctly interpreted by a user agent.

Yes, in theory. In real user agent world only some (rare?) invalid 
content can't be parsed in a meaningful way, because user agent have a 
level of sophistiphication that goes beyond the DTD specs, fortunately. 
In wcag should we admit this, or should we escape to theorical cases? (*)


(*) I remind that I'm always talking about text/html mime type, the 
99,99% (maybe more) of actual web. And I'm not pro tag-soup: but it's a 
truth that tag soup has forced user agent to copy with validity error, 
of course. This is the world now. At the point that validity is largerly 
irrelevant in most actual web even for AT. Sure, it would be better and 
we'd safer if content would be valid. In fact I agree to indicate that 
at higher level (even if I think this is not a cause of inaccessibility: 
the cause of inaccessibility should be addressed in a more general way 
by other guidelines, that include the relevant validity issues ( 
http://www.w3.org/2005/Talks/0908-wcag/validity-errors.html ): but I can 
live with this compromise).
Received on Wednesday, 9 November 2005 15:01:44 UTC

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