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Re: Thorny one - representing greek letters and formulae in an english page

From: Al Gilman <asgilman@iamdigex.net>
Date: Fri, 08 Feb 2002 17:12:19 -0500
Message-Id: <Version.32.20020208111934.0412acc0@pop.iamdigex.net>
To: "wai-ig list" <w3c-wai-ig@w3.org>
At 10:51 AM 2002-02-08 , Steve Carter wrote: 
One of our accessibility-course delegates has come up with something that has me stumped at this stage:  they want to represent greek letters on their page.  They currently use <FONT> to switch to the symbol font to do this, and another delegate argues for Gifs with ALT text.  My views are:
1) Font tags
Are wrong. 
2) gifs with ALT text:
Do not scale, but better for screen readers and older browsers
3) use a <SPAN> with locale change to greek
don't know if this would work, possibly more correct.  not sure about how most browsers will receive it.
4) Character entities :
Probably purest way, probably inaccessible to screen readers and older browsers
Does anybody have a view on this? or any decent resources I can review?

For one thing, character entities are usable in attribute values.  So, if you are targeting level three browsers or some such legacy window, you can do things like

<IMG TITLE="Gamma: CRT response exponent" ALT="&#unicodeNumberForTheGammaCharacterOfTheUpperOrLowerCaseAsYouWish; (Gamma)" SRC="/images/fonts/13-point/gamma.gif" CLASS="symbol math colorimetry">

This amounts to a poor man's OBJECT, q.v.

According to Lloyd a lot of screen readers would read the letter gamma as gamma anyway.  In the content guidelines work we have discussed using RUBY to insert phonetic and explanatory expansions.

In 20:20 hindsight we should have defined a SYMBOL entity in HTML and used it for acronyms, instead of getting people all tied up in knots arguing about which symbols are true ACRONYMs and which aren't.  But that's hindsight.

If the person in your group is working with a class in an organized institutional setting, they should look into getting members of the class to upgrade their browser to something that supports MathML and take the high-tech route.  Because they probably want to go for expressions and equations, too, and not just a few symbols here and there.

GIFs and ALTs are still a practical approach in some contexts.  Consult the EASI and MAVIS pages for more.

EASI Equal Access to Software and Information


Mathematics Accessible to Visually Impaired Students


In general, as Kynn says, the gamma is the sign but you didn't tell us the sense that goes with that sign.  How to handle it in the page coding depends on that sense.

Received on Friday, 8 February 2002 17:11:57 UTC

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