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[1.2] issue summary and proposal

From: Wendy Chisholm <wendy@w3.org>
Date: Thu, 02 Sep 2004 10:46:39 -0400
Message-ID: <4137324F.4060300@w3.org>
To: wai-gl <w3c-wai-gl@w3.org>


I have summarized the issues for Guideline 1.2 and reviewed real-world 
multimedia examples as background for this proposal.  My notes are at:

The following proposal is not perfect, but I hope it forms a good
starting point for discussion.

Guideline 1.2 Provide alternatives for multimedia content.

Level 1 Success Criteria for Guideline 1.2
1. Captions are provided for prerecorded multimedia.
(Editorial note: Propose that we don't create exceptions, but that
policy makers create exceptions. Refer to Telecom Act of 1996 which
defines "broadcast hours" for which captions are required as well as a
staggered time frame for requiring captions for programs that aired
before 1 January 1998)
2. Audio descriptions are provided for prerecorded multimedia.
(Editorial note: Again, we shouldn't create policy. Policy makers should
create it)
3. Transcripts are provided for prerecorded audio-only content that
contain dialog
(Editorial note: this should not apply to music with lyrics. Should this
be an exception or is it clear enough?)
4. A text alternative is provided for live audio-only content by
following Guideline 1.1.
(Editorial note: an internet radio stream would only need to provide a
description of the intent/character of the station, *not* every song
they play)
5. A text alternative is provided for live video-only content by
following Guideline 1.1.
(Editorial note: webcams would only need a text alternative associated
with the concept that the cam is pointing at, *not* every image that is
6. Applications that contain multimedia should follow Guidelines 4.1 and 4.2
7. If content is rebroadcast from another medium, the accessibility
features are intact.
(Editorial note: this is an exception in the current draft. Many 
reviewers found it confusing so I made it a success criterion. Not sure 
this is the best approach)

Level 2 Success Criteria for Guideline 1.2
1. Real-time captions are provided for live multimedia

Level 3 Success Criteria for Guideline 1.2
1. Sign Language interpretations are provided for multimedia (either
real-time or prerecorded) in the language of the dialog

Who Benefits from Guideline 1.2
(not proposing a change at this time, although they should be cleaned up)

Examples of Guideline 1.2

Example 1: a movie with audio description
Transcript of the first few minutes of, "Teaching Evolution Case
Studies, Bonnie Chen" (copyright WGBH and Clear Blue Sky Productions, Inc.)
Describer: A title, "Teaching Evolution Case Studies. Bonnie Chen." Now,
a teacher shows photographs.
Bonnie Chen: These are all shot at either the Everglades...for today you
just happen to be a species of wading bird that has a beak like this."
Describer: wooden tongue depressors
(Editorial note: will non-Americans know "wooden tongue depressors?")

Example 2: a captioned tutorial
A video shows how to tie a knot. The captions read,
 From Sample Transcript Formatting by Whit Anderson

Example 3: Animation of how a car engine works
An animation shows how a car engine works. There is no audio and the
animation is part of a tutorial that describes how an engine works. All
that is needed is a description of the image.
 From "How car engines work: Internal combustion"
(Editorial note: include some of the explanation? in fact, the
explanation given is not complete, so this is hypothetical)

Editorial note: Additional examples that should be developed
Example 4: internet radio stream vs short interview (diff between
ongoing/radio and finite/interview?)
Example 5: interactive animation/slideshow (Motorola example)
Example 6: webcam (africam)
Example 7: music video

Definitions (for the Glossary)

Content is an application if it responds to user input. (@@ all web
pages are interactive under this definition. trying to highlight the
difference between an application where the user agent doesn't handle
the events and content where the events are handled by the user agent)

audio description
Audio descriptions provide access to multimedia for people who are blind
or visually impaired by adding narration that describes actions,
characters, scene changes and on-screen text that can not be determined
from listening only to the soundtrack. This narration is limited to
pauses in dialog and provided in the spoken language of the audio.

audio-only presentation
An audio-only presentation only contains an audio track. Examples
include live, streaming radio and a recording of a screen reader
demonstration.  (need this?)

Captions provide access to multimedia for people who are deaf or hard of
hearing by converting a program's dialogue, sound effects, and narration
into words that appear on the screen. Captions are rendered in the
written language of the audio.

extended audio description
Audio description  is squeezed into pauses in dialog and therefore
limited in how much information is provided.  "Extended audio
description" is a method that periodically freezes the multimedia to
lengthen the time available for audio description.

The events are occurring in real-time as the user is watching or

Multimedia that is not live.


wendy a chisholm
world wide web consortium
web accessibility initiative
Received on Thursday, 2 September 2004 14:47:11 UTC

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