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Re: Highlights from Call Today

From: Charles McCathieNevile <charles@w3.org>
Date: Fri, 8 Nov 2002 05:41:26 -0500 (EST)
To: Joe Clark <joeclark@joeclark.org>
cc: WAI-GL <w3c-wai-gl@w3.org>
Message-ID: <Pine.LNX.4.30.0211080524130.3771-100000@tux.w3.org>

On Thu, 7 Nov 2002, Joe Clark wrote:

GV
>> 3. The presentation does not require the user to view captions and the
>> visual presentation simultaneously in order to understand the content.

CMN
As I read this, it appeared to suggest that people should be able to
understand what is happening from the captions alone. This might be true if
the captions include the audio description, but otherwise as Joe says people
are going to look at captions and the video, and the more they can multi-task
that the better they will understand the presentation.

Joe:
>Well, then you're not dealing with captioning as it has ever been
>known since the 1940s.
>
>I suppose it could be argued that, if one is reading captions, one
>is not "view[ing]... the visual presentation simultaneously." But
>this does not correspond to the way people watch captioned TV, for
>example. Research by Jensema--
>
>Carl J. Jensema, Sameh El Sharkawy, Ramalinga Sarma Danturthi,
>Robert Burch, and David Hsu, "Eye-movement patterns of
>captioned-television viewers," _American Annals of the Deaf_,
>145(3):275-285 (2000)
>
>-- documents that people spend most of their time looking at
>captions.
>[snip]
>
>But people spend *less* time looking at captions the *longer*
>they've been watching captioned TV, and that applied even to hearing
>subjects who had never watched captions before in their lives: After
>a few minutes of exposure, they had already gotten used to the
>experience of watching captions and were spending more time looking
>at the main picture.
>
>I can tell you from experience that, while reading caption text, one
>is nonetheless registering onscreen action through peripheral
>vision, which must not be underestimated.
>[snip]
>A confounding factor here is that online captions can be "better
>than reality," to use the nielsenism, in that you can pause the
>video but, in theory, keep captions and/or descriptions running. I
>suppose a strict reading of the requirement would force authors to
>use *only* systems that permitted random cessation of picture and/or
>captions at viewer whim.
>[snip]
>In what seems like a previous lifetime, I worked on a project that
>decoded Line 21 TV captions and put them up on the Web. Such
>captions would be outlawed by this provision even though they are,
>in fact, captions. Moreover, the provision would *outlaw open
>captioning altogether* because the captions and picture could not be
>independently controlled.
>
CMN
I think that the last paragraph is misunderstanding the statement. Reading
open captions but ignoring the rest of the presentation would seem to me to
be something the requirement is suggesting should be feasible, and lead to
understanding what is going on.

joe:
>Remove this section.
>
GV
>> Regard 1.2 Issues
>>
>> 2. all significant dialogue and sounds in multimedia content are
>> captioned
>>
>> 3. (does not replace current #3)  For Web that is real-time audio-only,
>> is not time-sensitive (e.g. not news, not emergency, etc.), and is not
>> interactive, a transcript or other non-audio equivalent is available
>> from the same URI.
Joe:
>Really? The same URI links to more than one thing?
>
CMN
This is perfectly possible. The URI
http://www.w3.org/WAI/References/QuickTips refers to a handful of different
things - in this case versions of the quicktips in different languages. The
technology for providing files of different formats at one URI is
well-established and used (for a trivial example in serving W3C images in
different formats, or for serving various bits of information as either HTML
or RDF). Does the group mean by this that content-negotiation must be
automatic, or is having human-readable links to different versios at the same
URI considered an acceptable way of meeting the requirement?

GV
>> [at bottom of level 1 put]
>>
>> NOTE:  Exceptions for amateur productions etc. are not made here because
>> they should be made in scope statements of policy setting agencies that
>> are using these guidelines.
Joe:
>You do realize you are essentially outlawing Internet radio under
>this plan?
>
>*Every* audio stream online would have to be captioned or
>transcribed. (What is "[an]other non-audio equivalent"? Semaphore?)

CMN
No, just pointing out that internet radio (and most radio, since it is
generally not captioned) is not accessible - in particular to people who are
Deaf. This shouldn't be much of a surprise, and it should be clear to policy
makers in particular that they need to decide how to set requirements. That
is, as I understand it, the purpose of this note.

There seems to be a terminology mismatch here - as I understand it Joe uses
captions to refer to a visual component of a presentation, such as a movie,
whereas on the Web it is possible and often the reality that captions which
can be presented visually are a seperate resource from the thing they caption
- just as closed captions are, until they get merged onto a screen.

Joe: [snipped]
GV
>> exception: if content is rebroadcast from another medium or resource
>> that complies to broadcast requirements for accessibility for the
>> location it was broadcast, the rebroadcast satisfies the checkpoint if
>> it complies with the other guidelines and if any existing accessibility
>> information (such as captions or audio description) are rendered in web
>> accessible format.   (See Level 3)
Joe:
>But the previous requirement bans any kind of captioning (and, I see
>now, description) that cannot be turned off and on independently of
>the picture.

CMN
I don't think Joe's comment is accurate for reasons I described above.
However I don't think that this is a valid exception - it seems to suggest
that if a policy body in some location decides that it isn't important to
caption something, and a broadcast is made there without captions, then one
can comply with this checkpoint by copying that. My objection is that this
confuses meeting a policy with meeting technical requirements for
accessibility. I don't think this exception should be retained, since the
case is covered by the Note above that says policy-makers (or in their
absence content producers) can decide what accessibility requirements to
actually meet, or require.

GV
>> exception:   content is rebroadcast from another medium or resource has
>> synchronized media equivalents for all audio and visual components of
>> time dependent presentations.
>
CMN
If the resource has synchronised equivalents then doesn't it already meet the
requirements? That should mean that it is not an exceptional case unless
those equivalents aren't actually meeting the requirements. And in that case
it should fail in my opinion.

Cheers

Chaals
Received on Friday, 8 November 2002 05:41:27 GMT

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