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RE: Proposed substantive change to media accessibility (Issue 2490)

From: Gregg Vanderheiden <gv@trace.wisc.edu>
Date: Tue, 26 Feb 2008 01:38:32 -0600
To: 'Sean Hayes' <Sean.Hayes@microsoft.com>, 'WCAG' <w3c-wai-gl@w3.org>
Message-id: <009e01c8784a$97168e50$0f6fa8c0@NC84301>
Hmmm

 

This one I am afraid is indeed substantially different.     And it also
frames the whole topic in 'non-blocking' language which is very hard to
parse (for me). 

 

In fact 1.2.1 is so layered - you have to parse it quite a bit to interpret
it. 

 

 

Yea,   I think this would make things a quite a bit harder to understand -
and of course - change the SC quite a bit.    

 


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

 

 


  _____  


From: w3c-wai-gl-request@w3.org [mailto:w3c-wai-gl-request@w3.org] On Behalf
Of Sean Hayes
Sent: Monday, February 25, 2008 2:19 PM
To: WCAG
Subject: Proposed substantive change to media accessibility (Issue 2490)

As discussed on the last teleconf, here is my proposal and rationale for
re-levelling the media accessibility requirements.

 

As you will recall in the previous email, In the current draft, at level A
the possible options for synchronised media are:

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

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  

 

Thus as we currently have it, a full text equivalent is seen as adequate
access (indeed preferred - given its appearance again at AAA) at level A for
people who have sight disabilities, but not for people who have hearing
disabilities. I guess the rationale for this unevenness is recorded
somewhere, I don't recall from the previous discussions what it was.

 

 In the discussion, I raised as an issue the relative difficulties of
producing each of these, and the real danger of media based websites
disregarding WCAG as a whole because they will be unable to meet the caption
and AD provisions, but that was rejected as a criterion for setting level,
so I'm not going to dwell on it too much here; even though I think it's very
important. But I do think the discrepancy above will eventually be picked up
on as a fault of WCAG, once it becomes clear what the choices actually are.

 

The full text alternative is very a high bar and exposes information in a
way which would make most copyright holders very uncomfortable, so it seems
incongruous to me at level A, even as an option, since these issues are
certainly going to make it very problematic for most mainstream media
providers; and option 2 above is probably going to be the only practical
choice. 

 

In my previous email, I introduced a concept of 'non-blocking', which
required that any information needed to correctly comprehend/use the page
was not presented in media alone, and could be used as a more
provider-friendly version of 'full text alternative' or 'text alternative'
to operate at level A. This would also be more technology neutral and future
proof; for example if a text based description technology came along, this
would actually be prevented by the current rules which require AD to be in
the soundtrack; even though it could be rendered by speech synthesis or
delivered via a refreshable Braille device, which might be more appropriate
in a mixed audience.

Another example is requiring a text equivalent for an MP3 tune; it would
seem that at minimum only a complete transcript of the lyrics is allowed to
achieve level A (it's pretty ambiguous  whether the draft would allow
captions in this case). It seems to me that users that are unable to hear
would probably not be blocked on a 'pay to downlowd' music site if they
could not read the lyrics of a snippet of a track, and that the name of the
tune, artist and possibly some recording notes/parental guidance would
probably be adequate for them to make a purchase decision.

 

The current full text alternative requires: 

"document including correctly sequenced text descriptions of all visual
settings, actions, speakers, and non-speech sounds, and transcript of all
dialogue combined with a means of achieving any outcomes that are achieved
using interaction (if any) during the
<http://www.w3.org/WAI/GL/WCAG20/#synchronizedmediadef> synchronized media "


And text equivalent requires:

"programmatically determined  <http://www.w3.org/WAI/GL/WCAG20/#textdef>
text that is used in place of
<http://www.w3.org/WAI/GL/WCAG20/#non-text-contentdef> non-text content, or
text that is used in addition to non-text content and referred to from the
<http://www.w3.org/WAI/GL/WCAG20/#programmaticallydetermineddef>
programmatically determined text"

 

Both of these have serious IP implications for providers, whereas
non-blocking would be:

content in a web page which is not used as the only means of conveying
information needed to comprehend a web page or perform an action needed to
operate a web page.

 

This ensures a basic level of accessibility in the presence of media and
allows much more flexibility at level A. Moving captions and AD at level AA
still allows jurisdictions which require them to set AA as the minimum bar,
which I suspect will be the typical case, but allows providers which can't
meet that to still have something to aim at, rather than not bothering at
all.

 

 

If we choose to address the issues above, then as I see it three possible
plans would be:

 

Plan 1 provide equity by allowing a full text equivalent for audio
disabilities, where at level A the options for synchronised media would be:

1)      Provide a descriptive identification, and a full text equivalent

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

At level AA, remove option (1) and add live to the other two options.

 

Plan 2 provide equity by removing the option of full text equivalent for
visual disabilities at level A, so that at level A the options for
synchronised media would be:

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

2)      Provide a descriptive identification and a full text equivalent

At level AA add live to option (1).

 

Plan 3 provide equity and allow a more readily achieved basic accessibility
option, where at level A the options for synchronised media are:

1)      Provide a descriptive identification, and  ensure media is non
blocking

 

At level AA).

Provide a descriptive identification, ensure media is non blocking , audio
describe all of the prerecorded video and caption all of the audio  

 

My preference (obviously) is plan 3 so I have proposed text for that below,
Plan 2 is IMO the one that will be 'real world' based on the existing draft
and is a smallish delta from my previous post.

 

 

 

 

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> .) 
*	Media: If it is (1)
<http://www.w3.org/WAI/GL/WCAG20/#synchronizedmediadef> synchronized media,
(2) [audio-only] or (3) [video-only] content. 

Note: media is covered under Guideline 1.2, which requires specific forms of
alternatives.

*	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. 

 

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 Basic Media Alternative: A descriptive identification is provided for
(1)  <http://www.w3.org/WAI/GL/WCAG20/#synchronizedmediadef> synchronized
media, (2) [audio-only] content or (3) [video-only] content; and that
content is [non-blocking]. (Level A) How to Meet 1.2.1 Understanding 1.2.1

 

 

1.2.2 Audio Description:  <http://www.w3.org/WAI/GL/WCAG20/#audiodescdef>
Audio description is provided for all [prerecorded] [video] content in
<http://www.w3.org/WAI/GL/WCAG20/#synchronizedmediadef> synchronized media.
(Level AA) How to Meet 1.2.2 Understanding 1.2.2

 

1.2.3 Captions:  <http://www.w3.org/WAI/GL/WCAG20/#captionsdef> Captions are
provided for all [audio] content in
<http://www.w3.org/WAI/GL/WCAG20/#synchronizedmediadef> synchronized media.
(Level AA) How to Meet 1.2.4 Understanding 1.2.3

 

 

1.2.4 Text Alternative: A  <http://www.w3.org/WAI/GL/WCAG20/#text-altdef>
text alternative that presents equivalent information of all [audio-only]
content and all [video-only] content is provided (Level AAA) How to Meet
1.2.4 Understanding 1.2.4

 

1.2.5 Sign Language:
<http://www.w3.org/WAI/GL/WCAG20/#sign-languageinterpdef> Sign language
interpretation is provided for all [audio] content in
<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

 

1.2.6 Audio Description (Extended):
<http://www.w3.org/WAI/GL/WCAG20/#extended-addef> Extended audio description
is provided for all [prerecorded] [video] content in
<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

 

1.2.7 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 

additional [audio] information that describes 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.

 

non-blocking content

content in a web page which is not used as the only means of conveying
information needed to comprehend a web page or perform an action needed to
operate a web page.

 

 

Sean Hayes
Incubation Lab
Accessibility Business Unit
Microsoft

 

Office:  +44 118 909 5867,  

Mobile: +44 7875 091385

 
Received on Tuesday, 26 February 2008 07:39:02 GMT

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