[thelist] AJAX and screen readers
David Kaufman
david at gigawatt.com
Tue Sep 5 23:51:00 CDT 2006
Matt Warden <mwarden at gmail.com> wrote:
> I am doing research on ways to use AJAX in a ADA-compliant manner. The
> issue I cannot figure out how to solve has to do with page updates.
Conventional wisdom used to be: Browse your site using Lynx or another
purely text-based browser. You can easily see (and read) the way that
your pages would be read to a visually impaired visitor by virtually all
"screen reader" software out there. Lynx, like the screen readers at
the time, had no Javascript capability whatsoever so, to comply with
Section 508 standards (as more and more publicly funded organizations in
the U.S. must) their sites cannot rely on Javascript for primary
functionality.
See http://www.section508.gov/
The AJAX must gracefully degrade to old-school links, making the same
content accessible via traditional static pages loaded the old fashioned
way. Think of it as SHOW: Synchronous HTML Over the Web :-)
Of course, these accessibility best-practices have been recommended for
ages:
- providing fallback-links within <noscript> tags for non-js-capable
browsers
- maintaining meaningful alt-tags on important images (such as
form-submission buttons) and *empty* alt-tags on the meaningless images
(to help screen readers bypass the clutter)
- providing invisible but screen-readable "skip to content" anchor links
to allow the screen "readee" to skip hearing your site's top and
left-nav menus recited over and over to them, on each page load, before
they can read the *content* on any page...
But almost no sites do any of it. Commercial web design tools barely
allow, much less encourage such practices, and unless you've got a
government-sized budget to develop and maintain sites that way, such
"ideals" never seem to become high enough priorities for businesses to
make actually make their sites truly accessible.
> My understanding is that the screen reader may not convey this
> [information updated via Javascript] to the user. My questions:
>
> (a) Is this true?
It certainly used to be. And even if the latest round of 2006 screen
readers don't completely ignore Javascript as they used to just 2-3 yeas
ago, most disabled users tend to be on fixed incomes, so only a very
small fraction of the "target population" will have the latest and
greatest software and/or hardware to run it so I'd say: be conservative
in what you assume about their O/S and software.
> The problem is that we do not have the equipment at the client site to
> test this out. Anyone with experience in this area... I'd love to hear
> your thoughts.
Google around and I'm sure you'll find whole communities of visually and
otherwise-abled users happy to give your site a test drive and tell you
what works and what doesn't.
And if you're serious about it, don't limit your planning to "visually
impaired" visitors -- take a moment to think about the motion impaired,
too. Lots folks can control their computers only by voice and can make
it can do anything you can do with a keyboard... but even the simplest
mouse actions are impossible for them. They don't have the javascript
limitations though, so as long as you added an
onkeypress="this.onClick()" wherever you had a
onclick="doSomethingFancy()" then visitors without motor ability were
still good to go...
Another thing to keep in mind is making sure that all the fonts used on
your site can be scaled to very large point sizes. This doesn't need to
be pretty: just possible! There are a lot more people with limited
vision who just can't read small or (to us) normal-sized text including
of course, most elderly folks, than there are users who need (and can
afford) screen reader software. Simply specifying base font sizes in
em's (instead of points or pixels) and then relative sizes as
percentages of increase or decrease can mean the difference between the
site being a joyful relief or hopelessly frustrating for millions of web
users out there.
> (d) Any other ideas?
IBM used to make demo software and development kits available that were
excellent. They are probably still leading the world in Accessible
Software (as well as creative euphemisms for disabilities):
http://www-306.ibm.com/able/dwnlds/index.html
http://www-306.ibm.com/able/partnerships/index.html
http://www-306.ibm.com/able/access_ibm/disability.html
And most clients asking for accessibility have some public funding and
some budget set aside for at least trying to implement some of it.
Hope this helps, and good luck to you, Matt!
-dave
More information about the thelist
mailing list