Comment on WAI-ARIA Role (math)

I'm glad that the math role is in the last call.  Although I'm partly
responsible for the present wording, I'd like to suggest a change to clarify
it.

Some documents use HTML elements such as <sup> and <sub> to represent math.
Eg
http://en.wikipedia.org/wiki/Quadratic_polynomial
has both images with alt text (in TeX) and "HTML math" (around the 6th
line).

<i>a</i><i>x</i><sup>2</sup> + <i>b</i><i>x</i> + <i>c</i> = 0

Another example later down is:

<i>f</i>(<i>x</i>)&nbsp;=&nbsp;<i>x</i><sup>2</sup>&nbsp;+&nbsp;<i>x</i>&nbsp;-&nbsp;2

Although I tend to think of these a "ASCII art", some people might not think
of them as "ASCII". So, I suggest the spec be changed from using the term
"ASCII art" in:

"However, since there exists significant amounts of legacy content that use
images and ASCII art to represent mathematical expressions..."

to something like:

"However, since there exists significant amounts of legacy content that use
images and textual approximations using ASCII art or HTML tags (eg, SUB and
SUP)  to represent mathematical expressions..."

There is a further clarification that is needed.  The section goes on to say

"The text equivalent used in such situations *SHOULD* be valid MathML or
TeX....images *SHOULD* also be labeled by text that describes the math
formula as it should be spoken, using the
aria-describedby<http://www.w3.org/TR/wai-aria/#aria-describedby>
attribute <http://www.w3.org/TR/wai-aria/#def_attribute>."

The sentence should start, "For images, ...".  and should be followed by a
sentence for what to do for "textual approximations".  They should be
wrapped in a div or span so that there is something to hang the role and
described by attributes.  There isn't (I think) a place to put TeX or
MathML, but if only simple elements like <i>, <sup>, and <sub> are used,
those are easy enough to figure out.  Others usages would be hard to figure
out (and hard to author without a tool), as would ASCII art.  If there were
a way to give TeX or MathML, that would be best, but I don't know how it
could be done.

It would be good to add examples using images and html tags to the best
practices section and to link to them in the explanation.  The wikipedia
page included above can serve as a source for some examples.

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