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Re: longdesc for an image used as a link

From: Al Gilman <asgilman@iamdigex.net>
Date: Thu, 25 Apr 2002 10:11:50 -0400
Message-Id: <200204251411.KAA1976403@smtp1.mail.iamworld.net>
To: w3c-wai-ig@w3.org
At 04:18 AM 2002-04-25 , goliver@accease.com wrote:
>Anyone ever felt compelled to use the longdesc
>attribute for an image used as a link?
>Anyone got any thoughts?

Basic strategy in attacking such a question:

a) what's the function [here of the description] for purposes of access to information by people with disabilities?

b) what are the options as to how to Web-provide an implementation of this function?

** why we care - (a)

Here's a disability-motivated scenario that motivates providing a description of the most endemic of image links: the logo linking to the home page of the site.

The basic kind of session is a coaching session.  A user with severe learning disabilities has mastered the mode of operation implemented by a dedicated intranet site designed strictly according to the rules suggested in

 Designing websites for people with learning disabilities

They are gradually adding sites to their repertory of where they control enough of the site idioms as representing navigation etc. concepts that they are familiar with so they can then go back independently to sites they have trained on.  This is working through a purely automated site tranforming portal, and sometimes it works better and sometimes it works less well.  But working in a coaching session with a counselor the client can move some sites out of the can't category into the can category.  The help is just needed during the first session or two with the site and after that the coach just does a check in watching virtually over their shoulder as they use the sites that they do use for additional skills the learner could incrementally add to their skills base.

In this context, the coach is a strong candidate to benefit from notes that provide a description and exegesis of the logo.  The coach needs to know what the site thinks the connections are between the themes in the graphic composition of the icon and the themes that motivate the existence of this site.  Then they can pick what will be appropriate as a mnemonic for this client, knowing their current skill set and orientation.  But the coach may be highly verbally oriented and baffled at the rationale for the icon selection without the designer's or sponsor's notes on the subject.

One take-away I would like to suggest from this example is that learning disabilities motivate heavy use of shared-application teleCollaboration techniques[1].  In the near term, it is easier to use the network to get the client and coach hooked up to the same browse session than to build sites that autoBaud to the client's level.  We know how to make sites adjustable, but at a penalty of a higher than normal cognitive competency level (about computer interace techniques) from the user, if they are to be autonomous in their operation.  

Learning difficulties blow away our assumption that the user is acting in isolation against an automated web.  Think in terms of a user using a website, observed by a coach, and the coach is tuning the user's preference indications so more sites know how to adapt automatically to this user's needs, and you are near the "near point" in a better future, that is to say the point in the "better future" that is nearest to now.

** how to do it. - (b) 

For now, this sort of thing is probably best addressed by a link from the foot of each page to some "about this site" pages that talk about the fonts used, the picture credits, and other sorts of miscellaneous annotations.  These are linked [potentially indirectly by two hops] from the foot of every page and this section of the site is also introduced conspicuously early in the home page for the site.  This in one sense could be either explained at that point as 'about' or 'help' or 'help and accessibility' or any of those.  But for people with learning disabilities it helps to standardize a few basic commands so let's just agree that there will always be a 'help' section on the site, and link early in the home page, so that the two-link pair of "home, help" always gets you to somwhere that the styling practices and notes like descriptions of the logos are _nearby_, with clearly marked or oriented paths to them from that point, not necessarily yet even immediatly on that page.

Aha!  Eureka.

There is the canard about "if the user can't get there in three links, they won't go there."  But accessibility is about how the exceptional cases are handled, non the mainstream.  So a lot of our techniques are at three links' remove or more.

The formula here is home + help + [up to three links, but well motivated links] should be the longest path from any page to the description of the logo used for the icon denoting the 'home' link.  And [foot] + about + [up to three links, but well motivated links] should always be there as an option.  There are just different users and the [foot] navigation vs. home navigation is something that you can't get everyone to do the same thing.

And similar rules.  We should be writing for the purposes of site design advice, acceptor patterns that describe the longest acceptable path per logical relationship that matters in any accessiblity scenario.


[1] The Rehabilitation Engineering Research Center on TeleRehabilitation in the U.S. has been running a successful pilot test of using videophones to allow just in time coaching by a job coach for a client in a work situation with need of same.  


>AccEase Ltd : Making on-line information accessible
>Phone : +64 9 846 6995
>Email : goliver@accease.com
Received on Thursday, 25 April 2002 10:11:54 UTC

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