W3C home > Mailing lists > Public > w3c-wai-ig@w3.org > January to March 2002

RE: WA - background-image in CSS - PRACTICAL APPLICATION

From: RUST Randal <RRust@COVANSYS.com>
Date: Fri, 18 Jan 2002 15:04:02 -0500
Message-ID: <37925254B67DD311876C009027B0FF9201D3A679@cbscolex01.cbsinc.com>
To: w3c-wai-ig@w3.org
Rather than continue the infighting, let's look at a practical use of images
in a CSS background.

Using the CSS-2 Spec, I can apply background images to the link element,
thereby creative a rollover menu without the use of Javascript.  Here is an
example:  http://www.meyerweb.com/eric/css/edge/complexspiral/demo.html

Now before anyone goes off on a tangent, please realize that the author of
this page, Eric Meyer, created the page strictly to show off some CSS-2
capabilities, in browsers that support CSS-2.

I'd like to get some PRACTICAL feedback on this, because in the document
that I am writing regarding accessible web pages, this is the method that I
suggest for rollovers.  I think it works much better than using Javascript.

In my document, the technique that I put forth DOES NOT use the image in the
background, but the background color changes, so that the user is more aware
that there is a link on the menu.

Does this technique conform to the WCAG guidelines?  Either with or without
the graphics.  This is a serious question, and I'd rather not get into any
conjecture, so please stick to the guidelines, not personal interpretation.

Randal Rust

-----Original Message-----
From: Kynn Bartlett [mailto:kynn-edapta@idyllmtn.com]
Sent: Friday, January 18, 2002 2:15 PM
To: Charles F. Munat; w3c-wai-ig@w3.org
Subject: Re: WA - background-image in CSS

At 10:36 AM -0800 1/18/02, Charles F. Munat wrote:
>Mr. Randall, when you suggest that some content is really 
>non-content, you are making a decision for your users, but you are 
>not making it for *all* your users. If something is non-content, why 
>include it at all? A good designer would eliminate it entirely.

That's not true at all, and you're hopelessly incorrect.  I'm amazed
to hear this from someone who really should know better.

>But by hiding it from non-visual users, you are segregating your 
>users into two groups -- visual and non-visual -- and you are saying 
>that this content is for visual users only.

No, that's absurd.  What you're saying here is that, for example, by
posting a decorative image which enhances the site for my users who
can see it, I'm somehow segragating users.  This is utter nonsense.

Here's an example.  Let's assume I'm creating a web site about people
in wheelchairs.  I create a graphic to illustrate an article, which is
a picture of someone in a wheelchair.  I give this an ALT of:

      <img src="wheelchair.jpg" alt="Many people use wheelchairs.">

What's the purpose of the image?  It's merely there to illustrate.
This is, according to WCAG1, a good idea -- it lets the user, who can
see the picture, know that they're on a page about wheelchairs,
for example.  This increases accessibility to people who have

However, by your (faulty) logic, I am also segregating my users.
I have made one class who get to see a picture of someone in a
wheelchair, and another class who get to see alt text.  This is
clearly saying "this content is for visual users only", right?

Of course, I do have an alt attribute, but note that information
got lost.  You don't know who the person in the wheelchair is,
or what they're doing.  You don't know how many are there.  You
don't know what gender or ethnicity that person is, or what they
are wearing.  You can't guess at the personal's social class,
or age, from the alt text.

So, I suppose, I could create a longdesc page for the image.  And
link it in appropriately with a longdesc attribute.  Okay, I do
that.  So what do I put on the longdesc page?  Well, I'm clearly
going to have to list all of that information above, right?
Because obviously, otherwise, information will get lost, and I will
be creating second class citizens -- those who can tell the age
of the person, roughly, by looking at the picture, and those who
cannot because they only see the alt text and the longdesc.

What other details do I include?  Should I put the name of the
person in the picture?  Obviously, if you know the pictured person
and can SEE the picture, you will get certain information which I
won't get if I know the person and I CAN'T see the picture.  I
should put the name of the location where the picture was taken,
and the approximate date and time.  I should put information on
the picture size and resolution, because obviously a user with
visual ability can see the image size, and the user without does
not have access to this information.  By not providing this
information, I am making two categories of people -- those who
get it visually and those who do not!

Of course, eventually I'll have to stop, because I'll exercise my
own judgment in deciding what is important enough to include in
the longdesc and what is not.  I'll probably do this based on my
own opinion of the function of the image in relationship to the
rest of the page.

But, wait, you've said THAT's wrong too!  Because I am exercising
my editorial judgment as the creator of the page in order to
discern what the intent is, and how it fits into the page
structure.  So I am once more being like a 1960s southern
shop owner who bans blacks from his shop!

Oh dear.

Then I read WCAG1 and I figure out that this may just be a
decorative image.  The real content -- "this is a page about
wheelchairs" and "lots of people use wheelchairs" -- is
reproduced in text in detail in the rest of the article.  And
this is just for decoration; just there for the benefit of
users who can see it, but not detracting from the usability of
the page for those who can't.

So maybe I'll just do this:

      <img src="wheelchair.jpg" alt="">

But wait!  That can't be right, even though it makes for a
perfectly understandable web page in Lynx and in screenreaders;
there doesn't seem to be any major information loss to the
primary purpose of the page.  But wait!  Now, since I no longer
have a longdesc or an alt attribute or any of that other stuff
I talked about before, the page can't be used for alternate
users such as "I want to know where the picture was taken and
who is in it!"  Oh no!  I am such a Nazi!

So ultimately I decide, just so that I don't get slammed on
WAI-IG or some other mailing list by web accessibility zealots,
I'll just remove my image altogether.  It's not really _necessary_
after all, since you can get the same message -- the one I intended,
which is "this is a page about wheelchairs and people using
them" -- from the text.

I'm likewise removing all my videos since you can get the same
content from transcripts, taking down all my sound files, replacing
all images with text descriptions -- long detailed ones! -- because
after all...I wouldn't want to make two classes of users.  Those
who can see images and can use my page, and those who can't see images
and can use my page.  That would just be UNTHINKABLE.


Kynn Bartlett <kynn@idyllmtn.com>                 http://kynn.com
Chief Technologist, Idyll Mountain            http://idyllmtn.com
Web Accessibility Expert-for-hire          http://kynn.com/resume
January Web Accessibility eCourse           http://kynn.com/+d201
Forthcoming: Teach Yourself CSS in 24 Hours
Received on Friday, 18 January 2002 15:02:26 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 19 July 2011 18:14:00 GMT