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Re: Disparity between WCAG 2.0 and HTML5 editors definition of text alternative

From: David Poehlman <david.poehlman@handsontechnologeyes.com>
Date: Fri, 11 Apr 2008 17:40:51 -0400
Message-ID: <001101c89c1c$b792d5d0$0901a8c0@HANDS>
To: "Steven Faulkner" <faulkner.steve@gmail.com>, "Ian Hickson" <ian@hixie.ch>
Cc: <public-html@w3.org>, <wai-xtech@w3.org>

I'm not sure that this is a deffinition and I'm also not sure that what it 
says is substantially different than the formal deffinition except that it 
doesn't go as far and who is to say that the formal deffinition is correct 
anyway?  Ian is actually supporting a longstanding view that the web needs 
to be transparent in whatever medium you are in whether visual, textual, 
auditory...  In other words, I don't see a conflict.

----- Original Message ----- 
From: "Steven Faulkner" <faulkner.steve@gmail.com>
To: "Ian Hickson" <ian@hixie.ch>
Cc: <public-html@w3.org>; <wai-xtech@w3.org>
Sent: Friday, April 11, 2008 5:30 PM
Subject: Disparity between WCAG 2.0 and HTML5 editors definition of text 
alternative



Ian, you asked for examples the HTML5 draft contradicts WCAG1/2
here is one you just provided yourself:

steve faulkner wrote:
> The Rorschach inkblot test example is covered in WCAG 2.0 [1] by the
> following:
>
> "Sometimes content is primarily intended to create a specific sensory
> experience that words cannot fully capture. Examples include a symphony
> performance, works of visual art etc. For such content, text
> alternatives at least identify the non-text content with a descriptive
> label and where possible, some descriptive text. If the reason for
> including the content in the page is known and can be described it is
> helpful to include that information."
>
> [1] 
> http://www.w3.org/TR/2007/WD-UNDERSTANDING-WCAG20-20071211/text-equiv-all.html

Ian hickson wrote:
"I disagree with this advice; I think it is harmful as it confuses titles
and captions with alternatives, and it removes the ability for an AT to
distinguish images that can be replaced by text with no indication of the
image's existence with images that are key to the content."

It would appear that there is a disparity between what WCAG 2.0
considers a text alternative and what you consider a text alternative

WCAG 2.0 definition:[http://www.w3.org/TR/WCAG20/#text-altdef]

"Text alternative
programmatically determined text that is used in place of non-text
content, or text that is used in addition to non-text content and
referred to from the programmatically determined text

Example: An image of a chart is described in text in the paragraph
after the chart. The short text-alternative for the chart indicates
that a description follows. "

Ian hickson's definition:
[http://lists.w3.org/Archives/Public/public-html/2008Apr/0285.html]

"The idea of alternative text is that you can substitute it for the image
without saying that there was an image, and the experience should be
equivalent."

I don't believe (but I may be wrong) that you are in a position to
enforce your own definition of what constitutes as a  "text
alternative" and use it to provide normative/informative statements
about alt use in the HTML5 specification.

I have previously brought this issue to the PF WG's attention [1] and
am awaiting their advice.

[1]http://lists.w3.org/Archives/Public/wai-xtech/2008Mar/0041.html

---------- Forwarded message ----------
From: Ian Hickson <ian@hixie.ch>
Date: 11 Apr 2008 20:52
Subject: Re: several messages relating to the alt="" attribute
To: Steven Faulkner <faulkner.steve@gmail.com>
Cc: public-html@w3.org


On Fri, 11 Apr 2008, Steven Faulkner wrote:
 >
 > this is not acceptable:
 >
 >   <figure>
 >    <img src="r14.jpeg">
 >    <legend>Rorschach inkblot test #14</legend>
 >   <figure>
 >
 > while this is:
 >
 >   <figure>
 >    <img src="r14.jpeg" alt="An abstract, ambiguous shape">
 >    <legend>Rorschach inkblot test #14</legend>
 >   <figure>


I disagree. I think "An abstract, ambiguous shape" is a fine title, but
 it's not alternative text.

 The idea of alternative text is that you can substitute it for the image
 without saying that there was an image, and the experience should be
 equivalent. For example:

   The <img src=cat.png alt=cat> sat on the <img src=mat.png alt=mat>.

 ...could be read as "The cat sat on the mat." and it would be fine.

 However, replacing an inkblot test with the text "an abstract, ambiguous
 shape" defeats the entire point of the test. The user knows full well what
 an inkblot test is, that's what the rest of the page says. The right thing
 is for the AT to indicate the presence of the image and try to provide a
 way for the user to investigate the image itself.

 Why is it not acceptable to omit the alt text?



 > The Rorschach inkblot test example is covered in WCAG 2.0 [1] by the
 > following:
 >
 > "Sometimes content is primarily intended to create a specific sensory
 > experience that words cannot fully capture. Examples include a symphony
 > performance, works of visual art etc. For such content, text
 > alternatives at least identify the non-text content with a descriptive
 > label and where possible, some descriptive text. If the reason for
 > including the content in the page is known and can be described it is
 > helpful to include that information."
 >

> [1] 
> http://www.w3.org/TR/2007/WD-UNDERSTANDING-WCAG20-20071211/text-equiv-all.html


I disagree with this advice; I think it is harmful as it confuses titles
 and captions with alternatives, and it removes the ability for an AT to
 distinguish images that can be replaced by text with no indication of the
 image's existence with images that are key to the content.


 --

Ian Hickson               U+1047E                )\._.,--....,'``.    fL
 http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
 Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'


-- 
with regards

Steve Faulkner
Technical Director - TPG Europe
Director - Web Accessibility Tools Consortium

www.paciellogroup.com | www.wat-c.org
Web Accessibility Toolbar -
http://www.paciellogroup.com/resources/wat-ie-about.html
Received on Friday, 11 April 2008 21:41:32 GMT

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