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Re: PRI-8 Alternate synchronized formats for audio-visual mater

From: eric hansen <ehansen@ets.org>
Date: Tue, 27 Apr 1999 03:56:44 -0400 (EDT)
To: w3c-wai-gl@w3.org
Message-id: <vines.Bh0E+wqK7rA@cips06.ets.org>
Re: PRI-8 Alternate synchronized formats for audio-visual materials

This memo attempts to address AC Member concerns regarding priorities for 
checkpoints 1.3 and 1.4.


I think that providing prerecorded auditory descriptions (checkpoint 1.3) 
should be Priority 2 rather than Priority 1, based on the definitions of 
Priorities. Synchronization of alternative equivalents (checkpoint 1.4), 
should also be Priority 2, at least for movies and animations.

I accept the WCAG document's definitions of "priority", which indicate that 
priority is determined by "impact" (that is, adverse influence on 
disability-group access caused by violation of a checkpoint).

What is the "basic" level of accessibility for a movie? I submit that it is 
simply a text transcript that collates the audio track information and the 
video track information. Failure to provide this "text-collation" 
equivalent for a movie would clearly render it impossible for individuals 
who are both deaf-and-blind to access the content. Collating the 
equivalents is essential because sequence (as in reading order) is 
essential; othewise one could lose track of the story-line of the movie. 
Without this text-collation equivalent, the movie will or may be completely 
inaccessible, thus making it a Priority 1 item. 

Does this Priority 1 solution (text collation) represent a high level of 
accessibility? It may about as accessible as it can be for individuals who 
are deaf-blind and rely on braille. The text-collation solution also 
provides basic accessibility for individuals who are deaf or who are blind, 
yet there are better solutions. For example, video and a synchronized text 
equivalent of the audio (i.e., captions) is a much better accessibility 
solution for an individual who is deaf. Also, an "auditory description" of 
the video synchronized with the audio track is a much better accessibility 
solution for someone who is blind. 

These Priority 2 solutions are superior and beyond the "basic" level of 
accessibility of Priority 1 checkpoints. As stated in the description of 
Priority 2 checkpoints, failure to implement the checkpoint(s) means that 
"one or more groups [in this case, individuals who are blind or who are 
deaf] will find it difficult to access information in the document." As 
further stated in the description of Priority 2, "Satisfying this 
checkpoint will remove significant barriers to accessing Web documents."  
The definition of Priority 2 fits checkpoints 1.3 and 1.4 very well.

Does failure to provide synchronization (checkpoint 1.4) and prerecorded 
auditory descriptions (checkpoint 1.3) make it impossible for individuals 
who are deaf or who are blind to access the content? No, it is not 
impossible, because users have the logically-ordered text collation defined 
at priority 1 (checkpoint 1.1). Thus, not only do checkpoints 1.3 and 1.4 
fit Priority 2 very well; they also fail to fit Priority 1.

Again, the text-collation equivalent provides only a "basic" level of 
accessibility. But that is all it purports to do at the Priority 1 level 
(essentially the single-A conformance level). Implementing Priority 2 and 
Priority 3 checkpoints makes it possible to achieve higher levels of 
conformance (or accessibility) (double-A and triple-A). This approach seems 
analogous to how priorities are assigned to checkpoints relating to tables. 
Basic accessibility is Priority 1 and refinements are Priority 2.

Please note that this argument does not depend upon the cost of 
implementing the solutions.


In terms of finding a solution to the current situation, I suggest the 

1. Add a note to checkpoint 1.1. (Highly recommended)

Add a note in checkpoint 1.1 (and perhaps in the glossary definition of 
equivalent) that states that correct presentation order is an integral part 
of what constitutes an equivalent or text equivalent. Following is a 

"Note X [for checkpoint 1.1]. A text equivalent must have a logical 
sequence (e.g., reading order). Ensuring logical sequence may require 
special attention for text equivalents that are combine two or more other 
text equivalents. For example, to preserve a proper presentation sequence, 
a text equivalent for a movie must collate segments of the text equivalent 
of the audio track with segments of the text equivalent for the video 

2. Make revisions to checkpoints 1.3 and 1.4 and reduce them from Priority 
1 to Priority 2 (Necessary)

The specific edits are found in a separate memo (Re: PRI-4 Animation and 

3. Add additional notes in the conformance section. (Optional)

Additional notes could be added to highlight and compensate for the fact 
that there are some checkpoints whose importance and potential benefit for 
users with disabilities (and others) is not adequately reflected in the 
current (impact-based) rating scheme. As I have indicated in times past, 
other methods for rating the checkpoints could have been used. For example, 
one could have rating scheme that incorporated information such as benefit 
estimates or even cost-benefit estimates. However, the current impact-based 
scheme is probably as reasonable as other methods we could create, and it 
is probably simpler! So we just need to stick with it consistently. Like 
any practical scheme, this scheme does not capture every nuance of what we 
mean by "importance." Material covered in Priority 2 and 3 checkpoints 
(e.g., 1.3, 1.4, etc.) may show unusually high value for people with 
disabilities, such that, under a different rating scheme, they might rate 
at the Priority 1 level.

Below is a suggested revision to notes in the conformance section of the 

"Note 1.{EH: Number added} Conformance levels are spelled out in text so 
they may be understood when rendered to speech."

{EH: New} "Note 2. Web content developers are encouraged to adhere to all 
checkpoints, including those beyond the conformance level that they choose. 
For example, even if Web content developer is working to achieve the 
single-A conformance level (which requires adherence only the Priority 1 
checkpoints), he or she should consider adhering to many of the Priority 2 
and 3 checkpoints as well. While violations of these Priority 2 and 3 
checkpoints do not make Web content impossible for disability groups, 
adhering to them can greatly improve disability access. Furthermore, 
adhering to many of the Priority 2 and 3 checkpoints can greatly improve 
usability for all users."

4. Add Notes in Individual Checkpoints (Optional)

One could say something like the following:

Note for checkpoint 1.3:

"Auditory descriptions, ({EH: Insert brief definition of auditory 
descriptions]}, tremendously enhance the "movie" experience for people who 
are blind {EH: Perhaps add "or who are both deaf and blind" if auditory 
descriptions include synthesized speech renderings.}.

One could also add similar notes to guideline 5 (re: natural languages) or 
its individual checkpoints.


I think that these suggestions address the major concerns voiced by the AC 

I think that this issue is of such importance that it is well worth 
reaching consensus. I believe that following the suggestions will help 
maintain credibility with the users of the document and assist 
significantly in the document's adoption.

Eric G. Hansen, Ph.D.
Development Scientist
Educational Testing Service
ETS 12-R
Rosedale Road
Princeton, NJ 08541
(W) 609-734-5615
(Fax) 609-734-1090
E-mail: ehansen@ets.org 
Received on Tuesday, 27 April 1999 03:59:57 UTC

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