W3C home > Mailing lists > Public > w3c-wai-gl@w3.org > July to September 2001

Re: Caption synchronization tolerance

From: geoff freed <geoff_freed@wgbh.org>
Date: 28 Aug 2001 08:22:32 -0400
Message-ID: <-1213135547geoff_freed@wgbh.org>
To: Guidelines WG <w3c-wai-gl@w3.org>, Gregg Vanderheiden <gv@trace.wisc.edu>, <w3c-wai-gl-request@w3.org>
CC: Larry Goldberg <larry_goldberg@wgbh.org>

>Live captioning is delayed for a number of reasons --
>including allowing people to read and correct the captions before
>transmission.   That delay is unavoidable today.   Yet that delay would
>be unacceptable in a captioned movie.

GF:
Actually, real-time captions are delayed primarily because it takes a few seconds for the captions to be written phonetically by a human, translated by computer and then inserted into the broadcast signal.  But, yes, stenocaptioners can make corrections as they write.

>Also, when doing training, you want the captions to lead any important
>visual event.  That is, you don’t want the person reading the caption
>when they should be looking at the screen to see something critical.

GF:
Perhaps, but this sort of decision is subjective and should be left to the author.  There is no industry-standard synchronization minimum or maximum used in captioning or audio description, and it would be impossible to specify a tolerance that could be universally applied even in the best of circumstances.  The guidelines should simply say that captions and descriptions should be "closely synchronized" or "reasonably synchronized" (take your pick) and leave it at that.  

When the time comes, I'd be happy to supply you with examples of captioned/AD multimedia for the techniques document, too.

Geoff/NCAM



On Monday, August 27, 2001, Gregg Vanderheiden <gv@trace.wisc.edu> wrote:
>>Meeting minutes say:
> >
> >>#67WC ask Geoff Freed or someone at WBGH.
> >>JW GV didn't want a number.
> >>Action WC: Ask Geoff.
>
>Geoff?  Larry?
>
>Gregg
>
>
>
>-- ------------------------------
>Gregg C Vanderheiden Ph.D.
>Professor - Human Factors
>Dept of Ind. Engr. - U of Wis.
>Director - Trace R & D Center
>Gv@trace.wisc.edu <mailto:Gv@trace.wisc.edu>, <http://trace.wisc.edu/>
>FAX 608/262-8848 
>For a list of our listserves send “lists” to listproc@trace.wisc.edu
><mailto:listproc@trace.wisc.edu>
>
>
>
>
Received on Tuesday, 28 August 2001 08:23:03 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:47:12 GMT