Roger,
The fact that this can be talked about at this length suggests that there is no good universal answer and whatever you pick will be wrong for some significant fraction of the population.
If the problem that you are trying to address is that screen readers do not handle common words on the web, which appears to be a problem of screen readers not understanding common web terms like homepage (or XML?) or of screen readers responding unpredictably to non-English words like va, the the question is really whether screen readers treat acronyms and abbreviations differently and whether they spell the letters out or try to pronounce them. I have no idea about how they behave in this case but English pronunciation rules are quite subtle and likely to be mangled by a piece of software.
If screen readers spell both types out as individual letters then it doen't matter if you use acronym or abbreviation, if they speak the title words then the best outcome might be to put the individual letters in the title to avoid making the presentation overly ponderous. Try reading something out loud, speaking all of the words in full whenever you see an acronym, it gets tedious, and we need to address accessibility and usability at the same time for a specific target audience, not for a theoretical audience for accessibility assists that may include people with cognitive impairment and a bunch of other problems that are harder to deal with than weird pronunciation from a screen reader.
Greg
On Tue, Aug 26, 2008 at 3:49 AM, Costello, Roger L.
<costello@mitre.org> wrote:
> use <abbr>SQL</abbr> if you want you
> audio-browser to say ess-cue-ell, and use
> <acronym>SQL</acronym> if you want
> it to say "Sequel"
This is a fantastic article:
http://redish.net/content/papers/interactions.html
A couple researchers sat down with 16 blind people to see how they use
the Web. Their results are very enlightening. Here's one of the
things they found:
Unusual words, acronyms, and abbreviations confuse screen readers, and
screen readers often read them wrong, e.g.
Word on the screen What the screen reader says
homepage hommapodge
LiveHelp livahelp
MEDLINE Medlynepalus
FY fie
VA va (like the Spanish for "go")
So, independent of whether you consider XML to be an abbreviation or an
acronym, do not depend on the tag alone:
<acronym>XML</acronym>
or
<abbr>XML</abbr>
For accessibility, always use the title attribute:
<acronym title="Extensible Markup Language">XML</acronym>
<abbr title="Extensible Markup Language">XML</abbr>
/Roger
