Re: PRI-4 Animation and Movies

Re: PRI-4 Animation and Movies

This memo discusses suggested changes in wording to checkpoint 1.3 and 1.4 
to address concerns of commenters.

Gregg Vanderheiden summarized the comment as follows:

"One of the commenters felt that many of the messages in the
public archive address important issues (in particular, Eric Hanson's
revision to checkpoint 1.3)

"They also felt that animation should be included in many places in the
document to accompany "movie" e.g. in Guideline 1, checkpoint 1.3. They
thought perhaps, "video and animation" would be better terms.  Reason for
the suggestion, is that they are referred to as video and animation in
multimedia literature."

To review Eric Hansen's suggested revisions, see:
http://lists.w3.org/Archives/Public/w3c-wai-gl/1999AprJun/0042.html


PART A: COMMENTS AND SUGGESTED GLOSSARY EXPLANATION

The 4/26/99 version of checkpoint 1.3 provided by G. Vanderheiden reads:

"LATEST SUGGESTED CHECKPOINT 1.3

"1.3 Until most audio-visual player technologies can use speech synthesis 
to
generate an auditory description of the video track from a text equivalent
(see checkpoint 1.1), provide an auditory description of the video track
(synchronized with the audio track).  This also applies to animations that
are accompanied by sound or time based user interaction.    [Priority 1]

"[Rationale:  there is no need for an audio description of a silent 
animation
unless it is tied to time based interaction with the page (e.g.  they need
to do something when a particular visual event occurs)  in which case it is
important to know when something is happening visually.  ]"


I think that a few issues should be noted:

1. This definition of "auditory description" differs from the definition 
found in the glossary. 

The passage indicates that an audio description can be synthesized. Yet the 
glossary (4/16/99 document) reads:

"One example of a non-text equivalent is an auditory description, 
pre-recorded speech that describes the key visual elements of a 
presentation and is synchronized with the audio track of the presentation 
(e.g., during natural pauses in the audio track). Auditory descriptions 
include information about actions, body language, graphics, and scene 
changes."
 
My suggested revision to it is as follows:

{EH: Revised, 4/27/99:}One example of a non-text equivalent is an _auditory 
description_, which is an auditory equivalent of a visual track of a video 
or animation, or multimedia presentation. To function properly, an audio 
description is usually synchronized with the audio track. (Information is 
spoken during the natural pauses in the audio track.) Auditory descriptions 
may include, for example, information about actions, body language, 
graphics, and scene changes. 

Following are my assumptions:

I assume that an auditory description is always auditory but that it does 
not matter what _kind_ of audio (synthesized speech OR prerecorded audio OR 
real-time audio OR can it be a mix of all).

I assume that an auditory description should ordinarily be synchronized 
with the auditory track. Yet it can be called an audio description even 
when not synchronized.

I assume that the text version of the audio description is simply the text 
equivalent of the video track. A text equivalent of the visual track is NOT 
an auditory equivalent although, through synthesized speech, a text 
equivalent can produce an auditory equivalent (e.g., an audio description).

2. Gregg Vanderheiden's definition treats animations differently from 
video.

I am assuming that the requirements that apply to videos also apply to 
animations.

The term animation, in my mind could be something a simple as an animated 
gif or as rich and extensive that it is essentially indistinguishable from 
a video. Thus, the terms "video" and "animation" have some overlap in their 
meaning. Both "video and animation" presentations can include audio as well 
as graphical content.


PART B: MY SUGGESTION FOR CHECKPOINT 1.3

My suggested wording for checkpoint 1.3 is as follows:

"1.3 Until most audio-visual player technologies can use speech synthesis 
to
generate an auditory description from a text equivalent of the visual track 
(see checkpoint 1.1), provide an auditory description of the video track 
for each audio-visual presentation (video or animation, or multimedia 
presentation) and synchronize it with the audio track. This does not apply 
to audio-visual presentations that are silent, unless the presentation 
requires a time-based user interaction [Priority 2] "

For comparison, the old (4/26/99) version is:

"1.3 Until most audio-visual player technologies can use speech synthesis 
to
generate an auditory description of the video track from a text equivalent
(see checkpoint 1.1), provide an auditory description of the video track
(synchronized with the audio track).  This also applies to animations that
are accompanied by sound or time based user interaction.    [Priority 2]

{EH: New. 4/27/99}

Changes to Checkpoint 1.1. There may need to be a change in checkpoint 1.1 
(e.g., "video and animation" instead of "video" AND "animation". I assume 
that a "multimedia presentation" simply composed of the other elements.). I 
invite others to see if they think changes are needed there.

PART C: MY SUGGESTION FOR CHECKPOINT 1.4

Revisions to Checkpoint 1.4

Note below that I have added reference to audio, since it, too, is a 
time-based presentation. I also added reference to text transcript of 
audio. Without these examples, checkpoint 1.4 only seems to cover the same 
ground as checkpoint 1.3. Priority 2 seems correct. Failure to synchronize 
does not make access impossible.

One question I have is whether synchronization between standalone audio 
(i.e., without video) and the text transcript is important enough and 
intended. 

{EH: 4/27/99, 2:50 hrs.} 
1.4 For any time-based presentation (e.g., video or animation, audio 
{EH:4/27/99. Added}, or multimedia presentation), synchronize equivalent 
alternatives {EH: "alternatives" may be OK here.}(e.g., captions, auditory 
descriptions, text transcript of stand-alone audio{EH:4/27/99. Added}) with 
the presentation. [Priority 2] 
Techniques for checkpoint 1.4
    {EH: New 4/26/99:} Note. Logical sequence (e.g., reading order) for 
text equivalents is Priority 1. (See note X for checkpoint 1.1)

{EH: Old from 4/16/99: 1.4 For any time-based presentation (e.g., a movie, 
animation, or multimedia presentation), synchronize equivalent alternatives 
(e.g., captions or auditory descriptions) with the presentation. [Priority 
1]

PART D: OTHER ISSUES

Synchronization is an important accessibility issue (e.g., synchronizing 
captions and video for people who are deaf; synchronizing audio 
descriptions and audio for people who are blind) and deserves to have a 
Priority 2 rating.

As others have stated the document sets standards for accessibility. It 
does not prescribe an implementation schedule for Web content developers.

=============================
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 03:59:44 UTC