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oops, equations, meant to send to all of WA IG

From: Steven McCaffrey <SMCCAFFR@MAIL.NYSED.GOV>
Date: Mon, 30 Jul 2001 08:32:06 -0400
Message-Id: <sb651b8f.067@MAIL.NYSED.GOV>
To: <w3c-wai-ig@w3.org>
Oops, I meant to send my comments regarding
equations to all of WAI IG and just realized I only sent them to Dave.

Here is what I sent.

Yes, I agree.  MATHML is not yet supported by screen readers.  
Personally, I prefer simple ASCII (or even LaTex source) representations because there is less chance of ambiguity than there might be with words.  
If ASCII is used, be careful of multiline fractions where dashes are used to represent the line separating numerator from denominator.  Since a screen reader reads one line at a time, the user will hear just the numerators then the next line the user will hear something like dash dash dash then the next line will be the sequence of denominators.  As you might imagine, this is very confusing.
It's better to do something like
[(x+2)/3] + [(x+4)/5] = 8.
     I have come across many sites that seem to be using ASCII but for some reason the exponent comes out on the base line.  Many sites have Einstein's famous equation expressing the equivalence of mass and energy as (what sounds like)
e = mc2.  Since I know what the equation is supposed to be, using the up arrow for exponentiation, it should be
e = mc^2, (happily, some sites have this representation).  Does anyone know why, on some sites, the exponent comes out on the baseline?

>>> <D.W.Russo@sas.com> 07/30/01 06:34AM >>>

I am not an expert, but I have been researching this issue a bit. 

For an overview of ways to make equations accessible, see these guidelines from the CPB/WGBH National Center for Accessible Media: 


In regard to MathML, today's browsers and accessibility software do not seem to provide significant MathML support. See the thread in this list: "MathML and screen readers" 

My general impression is that if your documents contain relatively few, simple equations, you might be able to do something that will give at least some visually-impaired people access to your equations. If you have a large library of documents with complex equations, the challenge is much greater. 


Received on Monday, 30 July 2001 08:34:39 UTC

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