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RE: Proposed reorganisation of media accessibility (Issue 2393)

From: Gregg Vanderheiden <gv@trace.wisc.edu>
Date: Tue, 26 Feb 2008 01:28:38 -0600
To: 'Sean Hayes' <Sean.Hayes@microsoft.com>, 'WCAG' <w3c-wai-gl@w3.org>
Message-id: <009601c87849$353b65d0$0f6fa8c0@NC84301>
Interesting. 

 

How about the following.  

It is the same as your proposal except.

 

1-       exception is moved back to provisions (doesn't really make sense in
the definition - but I see what you were trying to do)

2-       fixes a logic problem with 1.2.1  ("either this for live or that
for pre-recorded" doesn't work with a page level conformance.  They would
both have to be true)

3-       uses 'audio-only and video-only' rather than the new (undefined)
term 'basic media'

4-       split pre-recorded and live

5-       moved [prerecorded] and [live] to describe the media rather than
the audio or video track of the media

6-       removed   'of audio content' from caption provisions since that is
what captions caption.    Words are not needed for understanding and
actually make it harder to read. 

a.       e.g.  changed  <http://www.w3.org/WAI/GL/WCAG20/#captionsdef>
Captions are provided for all [audio] content in [live]
<http://www.w3.org/WAI/GL/WCAG20/#synchronizedmediadef> synchronized media"
to   " <http://www.w3.org/WAI/GL/WCAG20/#captionsdef> Captions are provided
for all [live]  <http://www.w3.org/WAI/GL/WCAG20/#synchronizedmediadef>
synchronized media"  

7-       (I'm not sure 'audio description of all video content' is needed
either (rather than just 'audio description') but it does make audio
description make more sense.   We can ask the group.)

8-       Put the pre-recorded back in (new) 1.2.8  (sign language). 

 

 

 

I believe that these changes (yours and mine together) do not change the
guidelines normatively - but just reorganize the provisions.    Others
should check this though. 

 

 

I like your definitions - but haven't compared them to what we have.

 


Gregg
 -- ------------------------------ 
Gregg C Vanderheiden Ph.D. 

 

Notes:

I'm assuming that the 'at least provide' language in 1.1.1 is intended to
apply to (1), (2), (3) and (4) in the Media, Test, Sensory exception, and
that the 'or' in 1.2.2 is not an exclusive or (which would make for a weird
interaction with level AA)

 

1)   Provide a descriptive identification, a full text equivalent and
caption all of the prerecorded audio [of the synchronized media]      

2)   Provide a descriptive identification, audio describe all of the
prerecorded video and caption all of the prerecorded audio 

3)   Provide a descriptive identification, a full text equivalent, audio
describe all of the prerecorded video and caption all of the prerecorded
audio    [audio describe is not required at Level A if you have  full text
equiv.]

 

At level AA the options are:

1)   Provide a descriptive identification, a full text equivalent, audio
describe all of the prerecorded video and caption all of the audio [of the
synchronized media]     

2)   Provide a descriptive identification, audio describe all of the
prerecorded video and caption all of the audio  [of the synchronized media]

 

In my reformulation, I have tried to bring these choices out a little more
clearly. I have used slightly different definitions, and provided tentative
(actual as opposed to circular) definitions for live and prerecorded, (the
30 second requirement for live is a SWAG in order to preserve testability,
but I think the principle is OK).

 

NB: One trick I have pulled here in order to prevent the media alternative
to text exception cropping up everywhere, is to move that exception into the
definition of synchronised media, this greatly simplifies the other
provisions but I'm not really happy with it. A better option would be to put
the exception on Guideline 1.2, but I'm not sure if we can do that.

 

 

 

 

1.1.1 Non-text Content: All
<http://www.w3.org/WAI/GL/WCAG20/#non-text-contentdef> non-text content has
a  <http://www.w3.org/WAI/GL/WCAG20/#text-altdef> text alternative that
presents equivalent information, except for the situations listed below.
(Level A)
<http://www.w3.org/WAI/WCAG20/quickref/20071218/Overview.php#qr-text-equiv-a
ll> How to Meet 1.1.1
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20071218/text-equiv
-all.html> Understanding 1.1.1

*	Controls, Input: If it is a control or accepts user input, then it
has a  <http://www.w3.org/WAI/GL/WCAG20/#namedef> name that describes its
purpose. (See also Guideline 4.1
<http://www.w3.org/WAI/GL/WCAG20/#ensure-compat> .) 
*	Test, Sensory: If it is (1) a test or exercise that
<http://www.w3.org/WAI/GL/WCAG20/#must-nontextdef> must be presented in
non-text format, or (2) primarily intended to create a
<http://www.w3.org/WAI/GL/WCAG20/#sensoryexpdef> specific sensory
experience, then text alternatives at least provide descriptive
identification of the non-text content.
*	 <http://www.w3.org/WAI/GL/WCAG20/#CAPTCHAdef> CAPTCHA: If it is to
confirm that content is being accessed by a person rather than a computer,
then text alternatives that identify and describe the purpose of the
non-text content are provided, and alternative forms of CAPTCHA using output
modes for different types of sensory perception are provided to accommodate
different disabilities.
*	Decoration, Formatting, Invisible: If it is
<http://www.w3.org/WAI/GL/WCAG20/#puredecdef> pure decoration, or used only
for visual formatting, or if it is not presented to users, then it is
implemented in a way that it can be ignored by
<http://www.w3.org/WAI/GL/WCAG20/#atdef> assistive technology.
*	Media: If it is (1)
<http://www.w3.org/WAI/GL/WCAG20/#synchronizedmediadef> synchronized media,
(2) [audio-only] or (3) [video-only] content ,then it is covered under
Guideline 1.2 success criteria.

 

Guideline 1.2 Media: Provide appropriate alternatives for media
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20071218/media-equi
v.html> Understanding Guideline 1.2

1.2.1 Prerecorded Audio-only and Video-only alternative: A [text
alternative] that presents equivalent information is provided for all
[prerecorded] [audio-only] or [prerecorded] [video-only] content except when
media is already an
<http://www.w3.org/WAI/GL/WCAG20/#multimedia-alt-textdef> alternative to
text and is clearly labeled as such. (Level A) How to Meet 1.2.1
Understanding 1.2.1

 

1.2.2 Live Audio-only and Video-only identification: A descriptive
identification is provided for all [live] [audio-only] or [live]
[video-only] content except . (Level A) How to Meet 1.2.2 Understanding
1.2.2

 

1.2.3 Synchronized Media Identification: A descriptive identification is
provided for  <http://www.w3.org/WAI/GL/WCAG20/#synchronizedmediadef>
synchronized media, (Level A) How to Meet 1.2.3 Understanding 1.2.3

 

1.2.4 Captions (Prerecorded):
<http://www.w3.org/WAI/GL/WCAG20/#captionsdef> Captions are provided for
[prerecorded]  <http://www.w3.org/WAI/GL/WCAG20/#synchronizedmediadef>
synchronized media except when media is already an
<http://www.w3.org/WAI/GL/WCAG20/#multimedia-alt-textdef> alternative to
text and is clearly labeled as such. (Level A) How to Meet 1.2.4
Understanding 1.2.4

 

1.2.5 Audio Description or Full Text Alternative: A
<http://www.w3.org/WAI/GL/WCAG20/#fullmultaltdef> full text alternative for
synchronized media including any interaction  or
<http://www.w3.org/WAI/GL/WCAG20/#audiodescdef> Audio description of the
[video] content  is provided for [prerecorded]
<http://www.w3.org/WAI/GL/WCAG20/#synchronizedmediadef> synchronized media
except when media is already an
<http://www.w3.org/WAI/GL/WCAG20/#multimedia-alt-textdef> alternative to
text and is clearly labeled as such. (Level A) How to Meet 1.2.5
Understanding 1.2.5

 

 

1.2.5 Captions (Live):  <http://www.w3.org/WAI/GL/WCAG20/#captionsdef>
Captions are provided for [live]
<http://www.w3.org/WAI/GL/WCAG20/#synchronizedmediadef> synchronized media.
(Level AA)
<http://www.w3.org/WAI/WCAG20/quickref/20071218/Overview.php#qr-media-equiv-
real-time-captions> How to Meet 1.2.3
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20071218/media-equi
v-real-time-captions.html> Understanding 1.2.3

 

1.2.6 Audio Description:  <http://www.w3.org/WAI/GL/WCAG20/#audiodescdef>
Audio description is provided for all [video] content in  [prerecorded]
<http://www.w3.org/WAI/GL/WCAG20/#synchronizedmediadef> synchronized media
(Level AA)
<http://www.w3.org/WAI/WCAG20/quickref/20071218/Overview.php#qr-media-equiv-
audio-desc-only> How to Meet 1.2.4
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20071218/media-equi
v-audio-desc-only.html> Understanding 1.2.4

 

 

1.2.7 Live Audio-only Alternative: A
<http://www.w3.org/WAI/GL/WCAG20/#text-altdef> text alternative is provided
that presents equivalent information for [live] [audio-only] content. (Level
AAA) How to Meet 1.2.2 Understanding 1.2.2

 

1.2.8 Sign Language:
<http://www.w3.org/WAI/GL/WCAG20/#sign-languageinterpdef> Sign language
interpretation is provided for all [audio] content in [prerecorded]
<http://www.w3.org/WAI/GL/WCAG20/#synchronizedmediadef> synchronized media.
(Level AAA)
<http://www.w3.org/WAI/WCAG20/quickref/20071218/Overview.php#qr-media-equiv-
sign> How to Meet 1.2.5
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20071218/media-equi
v-sign.html> Understanding 1.2.5

 

1.2.9 Audio Description (Extended):
<http://www.w3.org/WAI/GL/WCAG20/#extended-addef> Extended audio description
is provided for all [video] content in [prerecorded]
<http://www.w3.org/WAI/GL/WCAG20/#synchronizedmediadef> synchronized media
(Level AAA)
<http://www.w3.org/WAI/WCAG20/quickref/20071218/Overview.php#qr-media-equiv-
extended-ad> How to Meet 1.2.6
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20071218/media-equi
v-extended-ad.html> Understanding 1.2.6

 

1.2.10 Full Text Alternative: A
<http://www.w3.org/WAI/GL/WCAG20/#fullmultaltdef> full text alternative for
synchronized media including any interaction is provided for [prerecorded]
<http://www.w3.org/WAI/GL/WCAG20/#synchronizedmediadef> synchronized media.
(Level AAA)
<http://www.w3.org/WAI/WCAG20/quickref/20071218/Overview.php#qr-media-equiv-
text-doc> How to Meet 1.2.7
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20071218/media-equi
v-text-doc.html> Understanding 1.2.7

 

 

Definitions:

 

audio

the technology of sound reproduction

Note: audio can be created synthetically (including speech synthesis), or
recorded from real world sounds, or both.

 

audio description 

narration added to the soundtrack to describe important visual details that
cannot be understood from the main soundtrack alone 

Note 1: Audio description of video provides information about actions,
characters, scene changes, on-screen text, and other visual content. 

Note 2: In standard audio description, narration is added during existing
pauses in dialogue. (See also
<http://www.w3.org/WAI/GL/WCAG20/#extended-addef> extended audio
description.)

Note 3: Where all of the video information is already provided in existing
audio, no additional audio description is necessary

Note 4: Also called "video description" and "descriptive narration."

 

audio-only 

a time-based presentation that contains only [audio] (no [video] and no
interaction)

video-only 

a time-based presentation that contains only [video] (no [audio] and no
interaction)

live

information captured from  a real world event and transmitted to the
receiver within 30 seconds of the occurrence of the event 

Note: If information is completely computer generated, it is not live. 

 

pre-recorded: information that is not [live]

 

 

synchronized media 

[audio] or [video] synchronized with another format for presenting
information and/or with time-based interactive components, unless the media
is an  <http://www.w3.org/WAI/GL/WCAG20/#multimedia-alt-textdef> alternative
to text which is clearly labeled as such

 

video 

the technology of moving or sequenced pictures or images

Note: video can be made up of animated or photographic images, or both.

 

 

Sean Hayes
Incubation Lab
Accessibility Business Unit
Microsoft

 

Office:  +44 118 909 5867,  

Mobile: +44 7875 091385

 
Received on Tuesday, 26 February 2008 07:29:18 GMT

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