Re: General Exception for Essential Purpose

Al,

Ah Ha.  So the philosophy has changed.

You're saying the 2.0 philosophy is:

A page can do absolutely anything, images of text, all sorts of animations, 
uncaptioned audio, required mouse operation,  etc if they make sure that 
there's alternative page that strictly follows standards, with no 
exceptions, and provided

a) the user knows the alternatives that
are available b) the user can get there [into an interaction mode that works
for them] and c) it is all kept synchronously up to date.

If there's consensus on that...  we toss my proposed "exception" guideline.

I'm still uncomfortable because it's so darn difficult to verify that the 
alternative site is equivalent and up to date.  Especially if its 
dynamically generated.  it's tough enough to verify acessible pages at all 
and this adds an additional complication.  For example, you can't put 
corresponding pieces of original and alternative page together for comparison.

But I suppose in principle I've got to agree with the ideal.

Hmmm.  Even though it can be difficult to verify with a grey box approach, 
there would be software validation techniques that could simplfy checking 
if software is creating equivalent things.... but that's a thread for the 
ER group.

Anyway, thanks for explaining the new philosphy.  If anyone doesn't think 
that's the new philosopy please hollar before I relax too much...

Len



  At 04:43 PM 10/27/00 -0400, you wrote:
>At 09:41 AM 2000-10-27 -0400, Leonard R. Kasday wrote:
> >
> >At any rate, WCAG 1.0 had a guideline 11.4 on alternative accessible pages
> >that were allowed after the author made "best efforts".  If we import that
> >into WCAG 2.0, how will we word it?
> >
>
>AG::
>
>The "after the author made 'best efforts'" part of that checkpoint is
>
>- unenforceably vague
>- should be considered heuristic, i.e. not a part of the concrete verifiable
>'normative' requirements of this checkpoint.
>
>And furthermore,
>
>- alternate pages can be done well enough so that they do not incur even a P3
>violation.  They can add a P3-like benefit, as opposed to deficit in
>usability.  [There are both plusses and minuses, potentially, from such a
>structure.]
>
>In other words we should not lay any blanket negative valuation or prohibition
>on server-side diversity (a.k.a. alternate pages) _per se_.  This is cramping
>the content provider's solution options in a way that is unnecessary and
>unreasonable.
>
>So in WCAG 2 we drop the perjorative tone toward sites with server-side
>alternatives, and try to extract cleaner descriptions of the true
>make-or-break
>and major usability criteria.
>
>HOWEVER, all this still comes with a major WARNING that the content provider
>takes on the burden of ensuring that a) the user knows the alternatives that
>are available b) the user can get there [into an interaction mode that works
>for them] and c) it is all kept synchronously up to date.
>
>Even if pre-composing a short list of alternatives that the server
>understands,
>the content should still be passed over the wire with residual flexibility.
>The author cannot pre-figure-out all the cases the users will engender.
>
>The content providers don't have to cover all user cases with a single
>'universal' document or site version.  But they still have to be open to some
>client or middleware manipulation of what they put in each of the server-side
>alternatives.  A few tall poles do not a big tent make.  The poles have to be
>integrated with a flexible fabric.
>
>Al

--
Leonard R. Kasday, Ph.D.
Institute on Disabilities/UAP and Dept. of Electrical Engineering at Temple 
University
(215) 204-2247 (voice)                 (800) 750-7428 (TTY)
http://astro.temple.edu/~kasday         mailto:kasday@acm.org

Chair, W3C Web Accessibility Initiative Evaluation and Repair Tools Group
http://www.w3.org/WAI/ER/IG/

The WAVE web page accessibility evaluation assistant: 
http://www.temple.edu/inst_disabilities/piat/wave/

Received on Friday, 27 October 2000 17:14:51 UTC