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Comment on WAI-ARIA Role

From: Neil Soiffer <Neils@dessci.com>
Date: Wed, 20 Feb 2008 23:25:36 -0800
Message-ID: <d98bce170802202325s5ed35b21r253ab552e993240b@mail.gmail.com>
To: w3c-wai-pf@w3.org, public-pfwg-comments@w3.org
I work for Design Science, which is a W3C member.  I am a member of the
MathML Working Group and have been since its inception.  I am also chair of
the DAISY/Math Working Group.  That WG developed a spec that added MathML to
DAISY; it was approved about a year ago.  Our company developed MathPlayer,
the standard "plug-in" for IE to display MathML both visually and aurally.
MathPlayer works with JAWS, Window-Eyes, TextHELP, and other AT to make math
encoded with MathML accessible.  It is capable of generating speech,
synchronized highlighting, and braille from the MathML.

I have a request for an additional "role" to further support math
accessibility.  First, some context...

Because of browser implementation issues, MathML adoption has not been as
widespread as it should otherwise be.  A lot of people/sites, including
wikipedia, still use images for math.  However, the images often include alt
text or embedded comments that could be used to make the image accessible.
An idea that Design Science has been thinking about is writing JavaScript
that grabs the alt text or embedded comments and provides some level of
accessibility.  For example, if the image contains embedded MathML and
MathPlayer was installed, then the javascript could rewrite the page as one
containing MathML and MathPlayer could take over display and interaction
with AT.  If MathPlayer wasn't installed (for example, someone is running
Firefox on Linux), the JavaScript could still do the translation of MathML
to speech and braille.  It wouldn't be able to magnify or sync highlight.
If TeX or some other known format was found, the JavaScript could translate
it to MathML and then make it accessible.

The same JavaScript accessibility issues arise with this idea as with other
JavaScript -- AT doesn't know about the JavaScript and doesn't know that the
image (or div/span for JSMath) is really math.  If it did know, then it
could call on our interfaces (or eventually some standard expert handler
interface) and get an appropriate string to speak or string to send to the
braille display (math has it own braille codes and they are not identical
to what is spoken).

Now for the suggestion...  ARIA should have a way to say 'this element is
actually math'.  My non-expert suggestion for how to do this would be to add
a "math" role to the list of known roles.  'math' would be similar to 'grid'
in that it represents document structure and contains other elements.
Ideally, an extensible mechanism would be desirable, but math is an obvious
case that maps onto an existing W3C standard and would enhance existing
pages that don't use MathML.

As a real life example from Wikipedia [http://en.wikipedia.org/wiki/Nth_root],
the first image in the XHTML could potentially be made accessible if AT knew
about it by adding a role attribute as
<img class="tex" alt="\sqrt[n]{a}" role="math" src="
http://upload.wikimedia.org/math/9/a/2/9a2b6d33f3d62a1e8bd99c76f3cb79f5.png
">

[Note:  the alt text is present on the Wikipedia page.  The TeX was used to
generate the image in the first place]

Adding role="math" says that the alt text or comments in the image contains
information that can be used for accessibility purposes.  It alerts AT
software so that they can call on some expert math handler to get
information about how to handle the element.

Neil Soiffer
Senior Scientist
Design Science, Inc.
neils@dessci.com
www.dessci.com
~ Makers of Equation Editor, MathType, MathPlayer and MathFlow ~


 <http://en.wikipedia.org/wiki/Nth_root>
Received on Thursday, 21 February 2008 07:25:53 GMT

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