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Re: User Testing footage of header/id combinations, @summary and @longdesc for HTML5 WG

From: Eric Eggert <w3c@yatil.de>
Date: Fri, 14 Sep 2007 14:25:59 +0200
Message-Id: <F4DCE0BE-C93C-490B-99EB-8FD57109AAE0@yatil.de>
To: HTML WG <public-html@w3.org>

Tomas Caspers, an German accessibility expert, wanted me to share his  
thoughts about the @longdesc topic with you. He's referring to this  
WHAT WG blog entry: http://blog.whatwg.org/the-longdesc-lottery

Here are Tomas’ thoughts:

First of all thanks to Hixie for providing the stats - unfortunately  
(and predictably) this approach leads to the usual counter-claims  
that these are just data without any real implications for users of  
screen readers. Unfortunately (and predictably) the opponents don't  
(can't?) supply any data on the benefits of longdesc either (where  
»It's in the spec. so we must use it« does not constitute a benefit),  
so I'd like to provide you with some real world data.

Let me first give you some background info: I am working on a site  
http://www.einfach-fuer-alle.de/ run by a large German charity,  
Aktion Mensch. The site has been around since ca. '99/2000; the main  
topic is obviously web accessibility, tutorials, lobbying / awareness  
building and such. Aktion Mensch is also hosting a yearly high- 
profile competition, called the BIENE awards for the last 5 years. I  
am also working on the advisory council for the awards, where we  
developed and refined an immensely complex suite of accessibility  
tests (see: http://www.einfach-fuer-alle.de/award2006/kriterien/ for  
details). So, without grandstanding, I can safely establish that I  
know what I am doing. Also, we can safely assume that the sites I am  
working on have an above average audience with some form of handicap  
or another, since they are run by a charity that actively tries to  
engage PwD in the discussion concerning all matters related to web  
accessibility.

At »Einfach für Alle« we have been using the longdesc-attribute since  
the very beginning on select images such as charts, other graphical  
representations of data and on complex images such as screenshots in  
the tutorials. And yes, we've been using them properly (e.g.  
longdesc="foo.txt" or longdesc="bar.html"). When checking the server  
logs, we found that these longdescriptions received very, very little  
to no measurable traffic (based on traffic data from the last 7+ years).

So we decided to test this a couple of years ago (I would have to dig  
through the backup tapes, but IIRC it was around '03/'04) and  
replaced the descriptive texts with some generic message. This  
message basically said something like »You came here via the longdesc- 
attribute of an image. We'd like to hear from you if you find this  
way of supplying alternative text useful and if you use it on a  
regular basis on sites that employ those attributes. Please send an e- 
mail to...«. Feedback: None.

Next we collected all the longdesc attributes and changed their value  
to one single URI, so that they are all pointing to http:// 
www.einfach-fuer-alle.de/longdesc/generic.txt
In all those years the client received one single e-mail based on  
this text. Again: one. single. e-mail. And this even came from a  
blind visitor who does accessibility testing for a living (it said  
something like »Heh, gotcha!«). We check the stats on a regular basis  
and (filtering out bots) the traffic on those longdescriptions is  
essentially: zero.

If this isn't enough to convince the audience: the BIENE awards test  
is widely considered as the industry standard for checking the  
accessibility of large web sites here in Germany. It consists of four  
different stages (automated testing, expert evaluation, user testing,  
jury) with a strong emphasis on user testing. Since 2003, a total of  
1,100 web sites were entered into the competition. Out of these  
1,100, ca. 100 sites made it to the stage where they were tested by  
real users with just about any form of disability you can think of.

Most of these sites were not simple Wordpress installation with the  
default theme, but extra-large sites like state portals and  
parliaments, health insurances, the upper chamber of the federal  
parliament, the german federal reserve bank, the German Bundeswehr,  
Postbank Online-Banking (the largest bank here in .de and so on (see  
http://www.einfach-fuer-alle.de/award2006/preistraeger/ for a  
complete listing of awarded sites).

Quite a few of these sites do use longdesc on select images. During  
user testing (again, not limited to, but including the proverbial  
»blind user with JAWS«) we could not find a single instance where a  
user followed a longdesc (or a D-link for that matter). There were  
instances where the evaluators pointed users to a longdesc and asked  
them to explore these, but we can draw the safe assumption that the  
very users who would supposedly benefit the most do not use longdesc.

Conclusion: I'm sorry folks, but I'm afraid you will have to come up  
with something else other than longdesc.
Received on Friday, 14 September 2007 12:26:09 GMT

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