Re: Techniques for WCAG 2.0 Using aria-describedby to provide descriptions of objects ( LC-2848)

 Dear Laura Carlson ,

The Web Content Accessibility Guidelines Working Group has reviewed the
comments you sent [1] on the Last Call Working Draft [2] of the Techniques
for WCAG 2.0 published on 5 Sep 2013. Thank you for having taken the time
to review the document and to send us comments!

The Working Group's response to your comment is included below.

Please review it carefully and let us know by email at
public-comments-wcag20@w3.org if you agree with it or not before 21 January
2014. In case of disagreement, you are requested to provide a specific
solution for or a path to a consensus with the Working Group. If such a
consensus cannot be achieved, you will be given the opportunity to raise a
formal objection which will then be reviewed by the Director during the
transition of this document to the next stage in the W3C Recommendation
Track.

Thanks,

For the Web Content Accessibility Guidelines Working Group,
Michael Cooper
W3C Staff Contact

 1.
http://www.w3.org/mid/CAOavpvdR2oVvx2tymGbD3KraszTvCYNYJghCWsC_PyK1DMwE7Q@mail.gmail.com
 2. http://www.w3.org/TR/2013/NOTE-WCAG20-TECHS-20130905/


=====

Your comment on :
> 1. Title of the document
> 
> Using aria-describedby to provide descriptions of objects
> 
> 2. Location within the document
> 
> Text that states:
> 
> "A feature of WAI-ARIA is the ability to associate descriptive text
> with a section, drawing, form element, picture, and so on using the
> aria-describedby property. This is unlike longdesc, which typically
> required the author to create a separate file to describe a picture
> when it was preferred to have the descriptive text in prose as well so
> that it was readily available to all users. Yet, like longdesc,
> descriptive text is treated separately from the short name you would
> typically provide using the title or alt attributes in HTML. This is
> the preferred vehicle for providing long descriptions for elements in
> your document because the alternative is available to all, including
> sighted people who do not have assistive technology."
>
http://www.w3.org/WAI/GL/wiki/Using_aria-describedby_to_provide_descriptions_of_objects
> (16 July 2013 version)
> 
> 3. Concern
> 
> This information is incorrect.
> 
> Longdesc does not require the author to create a separate file to
> describe an image as explained in:
>
http://lists.w3.org/Archives/Public/public-comments-wcag20/2013Jul/0012.html
> 
> Additionally, with aria-describedby the description is forced upon
> screen reader users whether they want it or not. They cannot interact
> with it at will. Aria-describedby is read aloud without any user
> intervention, forcing the screen reader user to listen to it each and
> every time they encounter the image. The user is not able to control
> how they interact with the long description. None of this is a problem
> with longdesc as it supplies long descriptions on-demand and not by
> force. This choice is a critical user-requirement.
> 
> Forcing users to listen to long descriptions is an extremely negative
> and harmful user-experience as John Foliot has explained,
> “The ability to (mentally and literally) pause, step outside of the
> page flow to get a description of a complex image (because you cannot
> see it) and then return to the content flow AT EXACTLY THE SAME PLACE
> YOU LEFT OFF is a design feature, not a flaw. The key point about
> @longdesc (for screen readers) is that they are given a *choice* as to
> whether or not they want to hear what some might consider extraneous
> data or not - it is the difference between glancing at a sophisticated
> pie chart (for example) versus studying it. You, as a sighted user,
> have that choice (to glance or study), yet insisting that the full-on
> textual description be inserted into the content flow because the user
> is blind is tantamount to me holding your head in a fixed position and
> insisting that you explain aloud to me that pie chart before I allow
> you to continue reading the rest of the page.
> @longdesc is about user-choice!”
> http://lists.w3.org/Archives/Public/public-html/2011Mar/0736.html
> 
> The designed behavior of Screen Reading technology that supports
> aria-describedby is to automatically 'read aloud' the text string
> referenced by the attribute, whether or not the end-user actually
> wants this information. It will introduce a "force-fed" longer
> description on the Screen Reader user whether they want it or not.
> This is, understandably, an extremely disruptive user-experience and
> one we should be avoiding at all cost.
> 
> Aria-describedby is not a preferred method.
> 
> 4. Suggested change
> 
> Remove:
> 
> "This is unlike longdesc which typically required the author to create
> a separate file to describe a picture when it was preferred to have
> the descriptive text in prose as well so that it was readily available
> to all users. Yet, like longdesc, descriptive text is treated
> separately from the short name you would typically provide using the
> title or alt attributes in HTML. This is the preferred vehicle for
> providing long descriptions for elements in your document because the
> alternative is available to all, including sighted people who do not
> have assistive technology."
> 
> Add something such as:
> 
> Screen Reading technology that supports aria-describedby is
> automatically 'read aloud' forcing users to listen to descriptions
> each time a user encounters an object.
> 
> 5. Additional rationale for the comment
> 
> The Techniques for WCAG 2.0 document should treat ARIA and longdesc
> equitably and not be biased against the new longdesc spec.
>
https://dvcs.w3.org/hg/html-proposals/raw-file/default/longdesc1/longdesc.html
> 
> Please correct this situation.


Working Group Resolution (LC-2848):
Thank you for your comment.  We've reviewed your comment in conjunction
with similar remarks from another commenter, and are proposing changes to
address both.

The working group's intention is to offer information which authors can use
to understand ways to address WCAG 2.0 success criteria.  In response to
comments about the aria-describedby technique we are incorporating we are
proposing changes which will present about aria-describedby and longdesc in
the same way that recent changes to technique H45 introduced. 
Specifically, the second paragraph of the description for
http://www.w3.org/WAI/GL/wiki/Using_aria-describedby_to_provide_descriptions_of_objects
will read:

@@A feature of WAI-ARIA is the ability to associate descriptive text with a
section, drawing, form element, picture, and so on using the
aria-describedby property. This is similar to the longdesc attribute in
that both are useful for providing additional information to help users
understand complex images. Like longdesc, descriptive text provided using
aria-describedby is separate from the short name provided using the alt
attribute in HTML. Unlike longdesc, aria-describedby cannot reference
descriptions outside of the page containing the image. An advantage of
providing long descriptions using content from the same page as the image
is that the alternative is available to all, including sighted people who
do not have assistive technology. It is worth noting that as of the time of
writing (October 2013) some assistive technologies read aria-describedby
content immediately after an image's alt attribute information without user
activation - whereas current implementations of longdesc require the user
to take explicit action to read the additional description.

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Received on Thursday, 16 January 2014 20:57:40 UTC