

Re: Questions about WCAG 1.3 - A possible solution

From: Wendy A Chisholm <wendy@w3.org>
Date: Tue, 30 Nov 1999 17:15:03 -0500
Message-Id: <>
To: ehansen@ets.org, w3c-wai-gl@w3.org
Cc: w3c-wai-ua@w3.org

I think your proposals clarify many points.

The definitions should be added to the Techniques document and possible the 
errata page.

I like dropping the example at the end of 1.4, but I don't think we need to 
add the note.  (From my limited knowledge of SMIL) it does not appear to be 
possible to do it today and could be confusing.

I like your rewording of checkpoint 1.3 and am willing to adopt it in the 
errata page.  However, I think that checkpoint 1.3 should remain a priority 
1 because of the until user agents clause.  In today's world (where the 
text of the auditory description can not be synthesized to speech on the 
fly as well as synchronized with the primary audio track) 1.1 says to 
provide text equivalents, and 1.4 says to synchronize all equivalents.  If 
1.3 were not a P1 then that's all someone would have to do.  That's not 
acceptable for today's world.

I would agree that in the next release we could put checkpoint 1.4 before 1.3.

I also have questions about your 3rd proposal:

>3. Add a checkpoint (WCAG checkpoint 1.3A).
>The following revision makes clear that the even after user agents are able
>to produce synthesized-speech auditory descriptions from text, a
>prerecorded auditory description may still improve access. By having a
>distinct checkpoint for prerecorded auditory descriptions that does _not_
>have an "until user agents" clause, one can affirm the value of prerecorded
>auditory descriptions even _after_ they have been rendered partially
>obsolete by advances in user agent technology.

 >8 text snipped 8<

>"1.3A Provide a prerecorded auditory description of the visual track of a
>multimedia presentation. [Priority 3]"

I assume the value of prerecorded auditory descriptions comes from the 
inflections and nuances of a human reading the text.  It is my 
understanding that advances in speech synthesis technology are creating 
voices that sound much more "human."  With aural cascading style sheets I 
also assume we can pick up more of the inflections, intonations, etc. of 
human speech.  Therefore, I am not sure I agree with the need to create a 
new checkpoint.  However, this is based on the assumptions that this 
technology will be as good as promised.  This may be further in the future 
than the life of the proposed checkpoint.

>4. Fix the Techniques document.
>The Techniques should be modified to reflect the new emphasis. For example,
>ideally, the techniques could point to some approach or technology (e.g.,
>SMIL [?]) that could allow the captions, text transcript, and prerecorded
>auditory description to be generated automatically from the collated text
>transcript and its synchronization information.

The SMIL access note has several examples that we can refer people 
to.  Note that it does appear that a collated text transcript can be used 
to create both captions and an "on the fly" synthesized auditory 
description with SMIL 1.0 markup.  However, since the next version is still 
under discussion, I assume we'll be working with them on this.  The future 
looks bright already, since a systemAudioDesc test attribute is already 
described in SMIL-Boston. http://www.w3.org/TR/smil-boston/

>5. Make other minor adjustments in WCAG.
>A few other minor adjustments in WCAG might be necessary. For example, one
>might wish to mention collated text transcripts in a note in checkpoint

good idea.

>A note regarding "captions".
>The UAAG working group is considering referring to "closed captions" where
>WCAG refers simply to "captions". I think that there ought to be
>consistency between the documents. I have mixed feelings about that
>possible change. At this moment, I lean in favor of keeping the word
>"captions" as it is throughout the three documents.

"closed captions" means that the captions may be turned on or off, "open 
captions" are always displayed.  I suggest that we just use "captions" 
since one or the the other or both may be provided by an author.


wendy a chisholm (wac)
world wide web consortium (w3c)
web accessibility initiative (wai)
madison, wisconsin (madcity, wi)
united states of america (usa)
tel: +1 608 663 6346
Received on Tuesday, 30 November 1999 17:09:49 GMT
