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RE: RE: working definition of baseline

From: Gregg Vanderheiden <gv@trace.wisc.edu>
Date: Mon, 9 May 2005 00:05:31 -0500
To: "'Jason White'" <jasonw@ariel.its.unimelb.edu.au>, "'Web Content Guidelines'" <w3c-wai-gl@w3.org>
Message-Id: <20050509050531.44BD21CC3D7@m14.spamarrest.com>


  Then I don't think we should use baseline that way.  I suggest we talk
about baselines as follows.

To say that content conforms at a baseline - means that the content meets
all of the claimed SCs if the user had a user agent that met the baseline
(i.e. all baseline technologies were supported and turned on.   

Other's thoughts?


 -- ------------------------------ 
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 'Jason White'
Sent: Sunday, May 08, 2005 11:50 PM
To: 'Web Content Guidelines'
Subject: Re: RE: working definition of baseline

On Sun, May 08, 2005 at 11:25:25PM -0500, Gregg Vanderheiden wrote:
> Jason wrote (below)
> If my baseline is required to be the minimal set of technologies 
> needed for the content to be rendered at all, then I have failed the 
> success criterion because the metadata format isn't included in the 
> baseline as it degrades gracefully with respect to user agents that 
> don't support it
> - they just won't get the text alternatives.
> <end Jason>
> Thanks Jason - but I'm having trouble. 
> The only use of baseline I understood us to be using in conjunction 
> with WCAG conformance was one where the content would meet all 
> guidelines (at the
> level(s) claimed) if the baseline technology was there (present and 
> turned on).
> So how could it fail?  Or were you using baseline another way?   

The scenario I have in mind is one in which we define baseline to be only
those technologies absolutely *required* to render the content. My metadata
format can't be in the baseline, so defined, since by hypothesis, user
agents that don't support my metadata format can still render the content.
The baseline in this case might be HTML and JPEG images, for example.

With this baseline, guideline 1.1 isn't met because the text alternatives
are provided using my metadata format, which isn't, and can't be, included
in the baseline under this definition of "baseline". 
Now if all technologies in the baseline (HTML and JPEG) are supported and
enabled, guideline 1.1 won't be passed.

By contrast, if we have a broader definition of baseline, one that allows me
to include technologies that aren't strictly indispensable to the rendering
of the content, then I can include my metadata format in the baseline, in
which case (assuming as the baseline requires that it is turned on and
supported), I pass guideline 1.1.
Received on Monday, 9 May 2005 05:05:36 UTC

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