WebAIM - Web Accessibility In Mind

E-mail List Archives

RE: Is "this-or-that logo" adequate in an ALT text?


From: Leo Smith
Date: Aug 22, 2002 2:54PM

I am not sure there is going to be one agreed upon set of rules just
yet, as I think there is still much debate (or maybe it all took place
today on this list, in which case apologies, as I receive the digest

I have re-read the thread thus far, and in my mind one needs to
consider the various scenarios where ALT text is used instead of
the image element, and in each case consider the pros and cons
of the techniques we are proposing.

The first scenario is that of a screen reader user - the ALT text will
be used as a spoken alternative to the image, and in this case the
use of [ ] will not be of any use, and may even be a hindrance as it
will affect the first letter navigation of links in cases where images
are used as links and their ALT texts are used as the link
description. They may also affect the alpha listing of links.
Someone seemed to suggest that placing the link destination
information in the title attribute would solve this problem, that is:
<.img src="somelogo" alt="[some company logo]
But, will a screen reader index the title attribute value in favor of the
alt attribute value when it indexes the page's links - I have not
tested that so I do not know.

The second scenario is that where ALT text acts as a *visual*
replacement for the image. This would include situations where one
has images turned off in one's browser, or where text-only browsers
are being used. In these cases, using [ ] may well be of some
benefit. My preference would be to use these square parentheses
*only* where the ALT text is not a strict and complete replacement
for the information conveyed by the image. So, employ them for
purely visual images where generally only the *idea* can be
conveyed, or where the image conveys so much information (pie
chart example) that only a synopsis can realistically be offered with
ALT. In these cases, such images would probably tend to be used
less as links and so the pitfalls of using [ ] in ALT text would not be
as much of an issue. For example one *could* use "[bullet]" as the
ALT value for graphical bullets, which is certainly better than just
"bullet", but null alt text is probably still better here.

More often, images used as links are text-as-images that describe
the link destination - any ALT texts in these cases would be a
strict replication of the text-as-image content, and so would not be
contained in [ ] and thus avoid any pitfalls of using [ ]. I also like
the idea of using [ ] within ALT texts, to differentiate which part of
an ALT value is strictly verbatim replacement of the text-as-image,
and which part goes on to also describe extra idea or function
information about the image. Thus going back to our logo example,
I personally like:
<.img src="logo.gif" alt="Some Company [logo]">
<.img src="logo.gif" alt="Some Organization [go to home page]">
<.img src="logo.gif" alt="another company [logo]" title="go to
home page">

In these three examples, I think that the use of [ ] is fairly intuitive
and does not necessarily require some kind of explanation on the
site. These examples also avoid the problems with alpha link
listings and first letter navigation. I fear any title attribute values
would be lost in text only browsers, so the third example may not
be as useful for this scenario.

The last scenario I can think of at this late stage in the day (and I
am sure my scenarios are not exhaustive) is that of tooltips.
Agreed, using ALT text at tooltips is not _standard_ browser
behavior, but we cannot just ignore its use here when the dominant
browser out there uses it as such. In this scenario, I am not sure
whether using [ ] for any part of any alt text is useful or not. Indeed,
if we use a title attribute value in addition to ALT, then the user will
not see the ALT as a tooltip anyhow. I would say that in this
scenario, any literal information that the image conveys is entered
as the ALT value. Any additional information about the image's
function is placed in the title attribute. So for a company logo:
<.img src="logo.gif" alt="Some Company" title="go to Some
Company's home page">
Since the user in this scenario is using the visual information as
well as the tooltip, they do not need to have a tooltip that repeats
what the text-as-image spells out, nor do they need to be told that
it is the company logo (although I guess you could be explicit). The
tooltip does however provide extra information about the function of
the image that might be useful to a user in this scenario.

Any guidelines that we come up with will, I think, need to consider
all of these scenarios and probably more, and be something that
works for all of them.

That's my rather long 2 cents.


> There has been a lot of debate on this issue, and it's actually got me
> confused now - everyone has an opinon, and they're not all the same.
> At the risk of causing more disagreement (dontcha just love it), could
> someone summarise this thread into a few rules within one posting,
> based on all the comments received so far?

Leo Smith
Web Designer/Developer
USM Office of Publications and Marketing
University of Southern Maine

To subscribe, unsubscribe, or view list archives,
visit http://www.webaim.org/discussion/