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Re: Animated GIFs and accessibility guidelines

From: Kynn Bartlett <kynn@reef.com>
Date: Thu, 15 Feb 2001 07:59:51 -0800
Message-Id: <5.0.2.1.0.20010215074842.00ad4650@mail.idyllmtn.com>
To: Brian Kelly <b.kelly@ukoln.ac.uk>, w3c-wai-ig@w3.org
Here's my opinions, not as an official source but as an informed
person.  I'll also provide a little blurb about adaption which is
not meant as a plug for my employer's but rather as a viewpoint
from the perspective of dynamic interfaces.

At 01:04 AM 2/15/2001, Brian Kelly wrote:
>Guideline 7 at
>http://www.w3.org/TR/WCAG10/
>says
>"Ensure that moving, blinking, scrolling, or auto-updating objects or pages
>may be paused or stopped."
>and
>"Until user agents allow users to freeze moving content, avoid movement in
>pages."
>
>How does this apply to animated GIFs?

It means that animated GIFs should be "avoided".  ("Avoided" is
somewhere between "don't use" and "use them if you must, but only
if you understand the implications.")

In an Edapta model, it's okay to use animated GIFs as long as you
provide a quick and easy way for the user to control the presence
of them, and you replace them with something non-animated upon
request.  I personally would default to "no GIF animations" and
let the user turn that on in prefs, than assume GIF animations are
okay and let the user turn those _off_, but that may not be a
popular choice among many designers, and I can actually see an
argument for doing it the other way.

>Does it apply, for example, to the animated sponsorship ads at, for example,
>http://www.cast.org/bobby/

Yes.  As a quick example of inaccessibility, people with reading
problems might not be able to understand the scrolling list fast
enough before it vanishes from their view.

>I understood that movement on screens could cause screen readers to lose
>their focus.  Does this happen with animated GIFs?  If so, is this a
>concern?

I don't believe that animated GIFs cause this problem at all.  I've
never heard of such a thing happening, at least.

>Also, while looking at the Bobby page, the alt text for the GIF simply says
>"Scrolling list of sponsors, without mentioning their names (IBM, Microsoft,
>etc.).  Again does this conform to the WAI guidelines?

Conformance is hard to gauge as WAI uses terms like "appropriate",
but looking at practically, an accessibility barrier would present
itself to people who can't see images, if there is information
only available through the GIF.  There are several approaches to
eliminating this barrier:

1.  List the sponsors in the alt attribute.
2.  List the sponsors on a page at the other end of the longdesc
     attribute (I don't like this approach; longdesc is poorly
     supported so this helps few).
3.  List the sponsors elsewhere on the page and make sure that the
     alt attribute makes sense in context and isn't confusing.
4.  Make the image a link to a page that gives a textual listing
     of the sponsors.

So, in other words it isn't necessarily an accessibility barrier if
alt text isn't great, if the information is still accessible.  It
might be an accessibility speed bump.

>Like Nick, I don't want to pick on the Bobby site or the CAST staff, but it
>is a Web site that those with interests in accessibility will look at.

If you need another "target", you can always tear apart the HTML
Writers Guild's web site, which breaks 508 (not that it applies to
them) because of inability to skip navigation links.  Note, by the
way, that a certain K. Bartlett designed the HWG site. ;)


-- 
Kynn Bartlett <kynn@reef.com>
Technical Developer Liaison
Customer Management/Edapta
Reef North America
Tel +1 949-567-7006
________________________________________
ACCESSIBILITY IS DYNAMIC. TAKE CONTROL.
________________________________________
http://www.reef.com
Received on Thursday, 15 February 2001 10:55:34 GMT

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