W3C home > Mailing lists > Public > w3c-wai-ig@w3.org > January to March 2001

RE: Section 508 Question on Javascript - Section 1194.22, Paragraph (l)

From: Al Gilman <asgilman@iamdigex.net>
Date: Wed, 14 Feb 2001 15:42:10 -0500
Message-Id: <200102142027.PAA2955813@smtp2.mail.iamworld.net>
To: "Fitzgerald, Jimmie" <Jimmie.Fitzgerald@jbosc.ksc.nasa.gov>, w3c-wai-ig@w3.org
At 09:33 AM 2001-02-14 -0500, Fitzgerald, Jimmie wrote:
>As I've said before, we are more concerned here with 508 than we are with
>WAI from the W3C.  With that in mind...

I believe that your actual question deals with the _actual ergonomics_ of
dynamic web pages for people with disabilities, setting aside either
version of
guidelines.  This applied equally to people trying to apply either document.

>Does anyone have a page/site/snippet of code demonstrating JavaScript or
>VBScript for accessibility?

I don't have a good encyclopedic catalog of such resources, but it took me
less
than three minutes browsing the Web Content Accessibility working group site
<<http://www.w3.org/WAI/GL/>http://www.w3.org/WAI/GL/> to find, for example,

 Accessible DHTML Web pages
 <http://www.w3.org/2000/08/wcag-dhtml>http://www.w3.org/2000/08/wcag-dhtml/

I agree with Thatch that what we would like to have in this area is a lot more
than what we already have, however.  That's a "Join GL and help them work it
out..."

>I'd like to see a page with DHTML writing some dynamically created content
>with a script and an explanation of how and why that isn't accessible.  I'd
>then like to see the same page made accessible without sacrificing the DHTML
>portion of it.  If that can be done.
>
>I've seen lots of talk about this and the 508 is not clear on it at all but
>I've not seen anyone post url's to examples or anything like that.  Maybe I
>just missed it?
>

The issues are less than half understood, but there is some documented
understanding.

The burden really is on the dynamic content creator to create and
communicate a
static structure that the eyes-free user can internalize and use as
orientation
while navigating among the elements of the page and navigating through the
possible states of the dynamic elements.  Otherwise they will never find it
all, and even if they do they won't know that they have found it all.

 HCI Fundamentals and PWD Failure Modes
 <http://trace.wisc.edu/docs/ud4grid/#_Toc495220368>http://trace.wisc.edu/d
ocs/ud4grid/#_Toc495220368

A detailed example of a problem is one that has the User Agent group tied in
knots at the moment.  If there is some content that is only exposed when a
given mouse-dependent event happens, the user who is not using the mouse
has no
reasonable way of discovering that the content of the dynamically ephemeral
state is present in the page.

In a user-centric model of dynamic HTML, the element with a defined event
handler is an active element.  On the other hand the conventional tabbing
sequence implemented by browsers to reach all active elements only recognizes
HTML-defined actions, not HTML-defined events linked to script-encoded
actions.  So the tabbing bus doesn't stop there.  And the eyes-free user never
knows the difference.  That's an access failure.

That's a sample of the kind of accessibility failure that can come from the
use
of scripting without a careful process wrapping of accessibility evaluation by
skilled evaluators.  

It's not just Lynx.  You have to understand that people with visual
disabilities don't get exposed to the Web a page at a time.  Dynamic content
doesn't wreak havoc with the fully sighted user because the changes take place
against a persistent background of unchanged stuff.   The eyes-free or
low-vision Web user doesn't have that stability assist from peripheral stuff. 
They get the content of the page a peephole at a time.  They need to be
able to
do a sure-footed walk of the page structure to get to and inspect all its
parts.  The conventional idioms of dynamic page construction by scripting can
very easily turn the page to quicksand; to such shifty stuff underfoot that
the
process disintegrates.

Al

>I am all for accessibility but unless I can see some hard evidence related
>to script issues such as the one I am asking for here, I'll be inclined to
>continue scripting my little heart out.  I suppose I am failing to get the
>point on why Lynx or Script-less browsers are considered in the arena of the
>ADA.  American Disabilies Act right?  Not BDA (Browser Disability Act).
>Sorry if I sound a little insensitive here, not trying to be.  Just confused
>on all this talk about browsers.  Aren't we trying and really only trying to
>make sites accessible to *people* with disabilities?  Thought I had a clue
>about all this last week and this week, I am feeling pretty stupid about it
>all.
>
>
>
>Jim Fitzgerald
>
>-----Original Message-----
>From: Gregg Vanderheiden
[<mailto:gv@trace.wisc.edu%5D>mailto:gv@trace.wisc.edu]
>Sent: Wednesday, February 14, 2001 9:00 AM
>To: w3c-wai-ig@w3.org
>Subject: RE: Section 508 Question on Javascript - Section 1194.22,
>Paragraph (l)
>
>
>Hi Graham
>Here is the answer from Doug Wakefield at the Access Board  who put the
>regulations together
>With his permission I am reposting here  and on the SEC508 list
>
>
>Gregg
>
>
>
>Hello Gregg,
>
>In response to the question on the list concerning functional text in
>scripts:
>
>When a script has no associated text or label, the screen reader often reads
>some content of the script itself in a jumble of letters and words. We have
>chosen not to forbid the use of scripts, by rather to require that script
>functions provide text that will accurately tell a user the purpose of the
>script or action.
>
>Although there are some event handlers in JavaScript's that can pose some
>tricky access problems, the bigger problem is the manner in which scripts
>write to the screen.
>
>Doug Wakefield
>
>
>-- ------------------------------
>Gregg C Vanderheiden Ph.D.
>Professor - Human Factors
>Depts of Ind. and Biomed. Engr. - U of Wis.
>Director - Trace R & D Center
>Gv@trace.wisc.edu, <http://trace.wisc.edu/>http://trace.wisc.edu/
>FAX 608/262-8848
>For a list of our listserves send "lists" to listproc@trace.wisc.edu
>
>
> -----Original Message-----
>From: w3c-wai-ig-request@w3.org
[<mailto:w3c-wai-ig-request@w3.org%5D>mailto:w3c-wai-ig-request@w3.org]  On
>Behalf Of Graham Oliver
>Sent: Monday, February 12, 2001 2:56 PM
>To: w3c-wai-ig@w3.org
>Subject: Section 508 Question on Javascript - Section 1194.22,
>Paragraph (l)
>
>Hi
>I have tried to get to some sort of understanding of
>this on the Section 508 list at Trace, but am still in
>the land of confusion!
>
>The thread starts here
><http://trace.wisc.edu:8080/guest/archives/SEC508/sec508.0102/msg00000.htm
l>http://trace.wisc.edu:8080/guest/archives/SEC508/sec508.0102/msg00000.html
>
>I have been asked to write an article on accessibility
>which covers Section 508 so would like to give a
>reasonable interpretation of this regulation.
>
>Anyone care to have a go?
>
>Cheers
>Graham Oliver
>
>__________________________________________________
>Do You Yahoo!?
>Get personalized email addresses from Yahoo! Mail - only $35
>a year!  <http://personal.mail.yahoo.com/>http://personal.mail.yahoo.com/
>  
Received on Wednesday, 14 February 2001 15:27:33 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 19 July 2011 18:13:53 GMT