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RE: Baselines: how specific?

From: Gregg Vanderheiden <gv@trace.wisc.edu>
Date: Thu, 20 Apr 2006 09:00:51 -0500
To: <w3c-wai-gl@w3.org>
Message-ID: <004501c66482$d6d531a0$ee8cfea9@NC6000BAK>

Good discussion.

We are revising the baseline doc right now.  Will try to capture some of
this but it would be good to think of some good general language that makes
this clear - and shows how to write baselines.   More on this will follow

How about the following

1) A technology or feature isn't in the baseline unless it is named in the
2) Baseline 'items' can include technologies, specific features, or well
defined collections.
3) If a collection or general technology is specified in the baseline, the
assumption is that all of its subparts, features, modules etc. are in the
baseline unless excluded in the baseline definition.
4) "embed" could be listed in a baseline definition but is not part of HTML

Thoughts on the above?  


 -- ------------------------------ 
Gregg C Vanderheiden Ph.D. 
Professor - Ind. Engr. & BioMed Engr.
Director - Trace R & D Center 
University of Wisconsin-Madison 
The Player for my DSS sound file is at http://tinyurl.com/dho6b 

-----Original Message-----
From: w3c-wai-gl-request@w3.org [mailto:w3c-wai-gl-request@w3.org] On Behalf
Of Gez Lemon
Sent: Tuesday, March 14, 2006 12:27 PM
To: w3c-wai-gl@w3.org
Subject: Baselines: how specific?

Hi Christophe,

A list of technologies is a simple binary representation that does not do
justice to the reality of incomplete implementations by user agents.

That's very true, and quite ironic given that UAAG couldn't be used because
no user-agents adhere to it. It gets difficult, as we could easily end up
with a situation where HTML couldn't be included as a technology because
it's not properly supported.

Some websites that puts HTML 4.01 in their baseline will assume that every
feature is supported, while others will assume that object, link, longdesc,
etc are not adequately supported by the user agents of a significant
percentage of their visitors. This means that some websites will use
fall-back techniques such as 'embed', while others will not.

This takes me to another aspect of my original question: if websites use
'embed' or other non-standard features, shouldn't that be part of the
baseline also? Just specifying 'HTML 4.01' in the baseline would be

Some good points, but how would you specify a non-technology in the
baseline? Putting, "non-standard HTML" wouldn't be acceptable. Maybe a
better approach would be to assume that all features of a technology are
supported, and introduce a "Repair Techniques" or similar section, where
authors can document how they overcome known shortcomings in technologies.

The third aspect of my question is whether a baseline should specify which
version or profile of a technology is assumed. For example, is it sufficient
to say "HTML 4.01" or is it necessary to say "HTML 4.01 Strict"?
(I'm in favour of the latter, more specific, approach.) </quote>

I'm also in favour of the latter, but can't help thinking that the extra
information isn't really useful to anyone in terms of a conformance claim.
If structure, presentation, and behaviour have been separated (a requirement
of the guidelines), is there any benefit in knowing whether HTML as a
technology is transitional or strict?

Some W3C technologies have been "modularized": is it necessary to  specify
which modules are assumed to be supported? I think it is.
  The question about modularizaton also throws a different light on the
question  of specifying whether specific features (e.g. object in HTML) can
 mentioned: after all, modules are collections of such features.

Modules can also packaged, and I would personally prefer the technologies in
the baseline to be as succinct as possible. For example, XHTML 1.0 is based
on XHTML abstract modules [1], so I wouldn't see the point of listing them
all individually if they were included as a collection (including other
modular flavours of XML markup languages). I can see the purpose of
including individual modules, such as XForm, but not the features of those

Is it also necessary to specify which MIME types are assumed to be
supported? This is relevant when using XHTML 1.0.

Another excellent point. MIME types aren't included in the definition of
"technology", unless "data formats" covers this, but I would like to see it


Best regards,


Supplement your vitamins
Received on Thursday, 20 April 2006 14:01:01 UTC

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