W3C home > Mailing lists > Public > public-comments-wcag20@w3.org > July 2013

Techniques for WCAG 2.0 Using aria-describedby to provide descriptions of objects

From: Laura Carlson <laura.lee.carlson@gmail.com>
Date: Thu, 18 Jul 2013 15:39:03 -0500
Message-ID: <CAOavpvdR2oVvx2tymGbD3KraszTvCYNYJghCWsC_PyK1DMwE7Q@mail.gmail.com>
To: public-comments-wcag20@w3.org
Cc: Charles McCathieNevile <w3b@chaals.com>, Vlad Alexander <vlad.alexander@xstandard.com>, John Foliot <john@foliot.ca>, Catherine Roy <ecrire@catherine-roy.net>
Hi WCAG,

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.

Best Regards,
Laura
--
Laura L. Carlson
Received on Thursday, 18 July 2013 20:40:07 UTC

This archive was generated by hypermail 2.3.1 : Saturday, 14 July 2018 08:34:47 UTC