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Re: User agent capabilities [was Agenda

From: Leonard R. Kasday <kasday@acm.org>
Date: Fri, 08 Dec 2000 13:37:05 -0500
Message-Id: <4.3.2.7.2.20001208132918.029f0f00@pop3.concentric.net>
To: Charles McCathieNevile <charles@w3.org>
Cc: <w3c-wai-gl@w3.org>
Charles,

There's still something I don't get here.  The WCAG draft 
http://www.w3.org/WAI/GL/WCAG20/  still says that people will be able to 
use it to judge conformance.

Now suppose I have a web page that has LONGDESC but no D links.  The way 
you've described it,  I don't see how I can figure out the conformance from 
the guidelines because LONGDESC isn't even in the guidelines.  It's in the 
techniques which are not normative.

And even if we brought your statement into the guidelines, viz
quote
HTML: Use the longdesc attribute to link to a full description. This can be
provided in the same page. This requires browsers that support longdesc, so
does not work for (almost anything available today, but we probably want to
have a way of saying this that future proffs us a bit). Alternatively, link
a letter 'D' immediately after the object being described to the description.
This works in anything. (because somewhere we have stated that we expect
links to work in all browsers...)"
unquote

that doesn't say whether D is required.

So how do we measure conformance?

Len





At 11:28 AM 12/8/00 -0500, Charles McCathieNevile wrote:
>No, I am after something a bit different.
>
>We say in the guidelines "provide functional equivalents that can be used in
>different circumstances - by people who are deaf, blind, unable to read huge
>slabs of text, ..."
>
>Then in the checkpoints we say "provide text equivalents for all non-text
>elements".
>
>(then in the glossary we say that non-text elements are ones that cannot be
>rendered as text - they do include ASCII art but may not include accessibly
>designed SVG images...)
>
>Then in the techniques we say:
>"HTML: Use the alt attribute to provide a short functional equivalent. This
>needs to allow the user to scan quickly through the page, so information that
>is more than a sentence or so should normally be a long description (see
>below).
>
>And somewhere further on (or maybe this is a checkpoint)...
>
>A long description must be provided for complex information presented in the
>a non-text element.
>
>HTML: Use the longdesc attribute to link to a full description. This can be
>provided in the same page. This requires browsers that support longdesc, so
>does not work for (almost anything available today, but we probably want to
>have a way of saying this that future proffs us a bit). Alternatively, link
>a letter 'D' immediately after the object being described to the description.
>This works in anything. (because somewhere we have stated that we expect
>links to work in all browsers...)"
>
>Does that make it clearer? I guess we will need to go a  few times around to
>get this sorted.
>
>Cheers
>
>Charles
>
>
>On Fri, 8 Dec 2000, Leonard R. Kasday wrote:
>
>   Charles,
>
>   Let me check if I understand what you mean with an example.
>
>   Take LONGDESC for example.
>
>   and consider a WCAG that
>   1. omitted LONGDESC from the baseline requirement
>   2. said "to accommodate users with user agents that support LONGDESC it is
>   sufficient to use that that attribute to give a more detailed description"
>   3. also said  "to accommodate users with agents that don't support
>   LONGDESC, use a "D link" as follows etc..."
>
>   Now, for purposes of discussion, please put aside for now whether we
>   actually want to omit LONGDESC from the baseline, and also please also put
>   aside whether the rest of this example is worded optimally or complete.
>
>   I want to ask just this narrower question: is this the type of Guideline
>   document you are advocating?
>
>   Len
>
>   p.s.
>
>   I'd personally support that sort of document.  Then the only issue will be
>   whether WAI will want to say anything anywhere about what sets of user
>   agent capabilities might be assumed and how the guidelines filter thru
>   those assumptions.
>
>
>   At 03:36 PM 12/7/00 -0500, Charles McCathieNevile wrote:
>   >Actually, I think that it is a much lower priority work item for us to 
> create
>   >profiles of WCAG for different constraints provided by certain 
> organisations.
>   >It seems to me much more the job of whoever is placing the constraints to
>   >demonstrate tht for their purposes a particular requirement of universal
>   >accessibility is not relevant.
>   >
>   >For example, we could in principle assume that everyone in the world uses
>   >iCab (the japanese version) with the speech and keyboard control systems
>   >native to the Macintosh, and work out what are the requirements that 
> we can
>   >ignore, or can list the problems that occur, based on that. Essentially I
>   >think we have a critical requirement to make one such decision: What 
> is the
>   >baseline requirements for a User Agent?
>   >
>   >Beyond this, we should be able to name the problems that each checkpoint
>   >addresses. But there are limits to how far we can track each tool set and
>   >which checkpoints are relevant to it.
>   >
>   >(For me this is in the same basket as setting policy. i.e. it belongs 
> to the
>   >people who are doing it.)
>   >
>   >Charles.
>   >
>   >On Thu, 7 Dec 2000, Leonard R. Kasday wrote:
>   >
>   >   Another user agent issue I face is that it depends on the user group.
>   >
>   >   For example, if a business or agency provides its employess with user
>   >   agents having certain capabilities, it doesn't have to worry about 
> older
>   >   user agents, for pages only used by those employees.   In other 
> words, we
>   >   can assume more for intranet pages than for internet pages.  (I'm 
> dealing
>   >   with this as we speak BTW).
>   >
>   >   I think this is yet another argument for having a document (or 
> section of a
>   >   document) that deals only with accessibility as a function of user 
> agent,
>   >   and omits "requirements" or "compliance".
>   >
>   >   Requirements for compliance should be in a different document (or 
> document
>   >   section), which takes into account the user population (e.g. public vs.
>   >   employee) and factors against which there may be a tradeoff with
>   >   accessibility (e.g. "essential purpose" ).
>   >
>   >   I think this will save time in the long run, since we'll otherwise have
>   >   perpetual arguments due to different people having different 
> situations in
>   >   mind.
>   >
>   >   Len
>   >
>
>   --
>   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/
>
>
>--
>Charles McCathieNevile    mailto:charles@w3.org    phone: +61 (0) 409 134 136
>W3C Web Accessibility Initiative                      http://www.w3.org/WAI
>Location: I-cubed, 110 Victoria Street, Carlton VIC 3053, Australia
>September - November 2000:
>W3C INRIA, 2004 Route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex, 
>France

--
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, 8 December 2000 13:37:31 GMT

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