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Re: RE: working definition of baseline

From: 'Jason White' <jasonw@ariel.its.unimelb.edu.au>
Date: Mon, 9 May 2005 14:49:42 +1000
To: "'Web Content Guidelines'" <w3c-wai-gl@w3.org>
Message-ID: <20050509044942.GA6012@jdc>

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 04:50:35 UTC

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