WebAIM - Web Accessibility In Mind

E-mail List Archives

Re: Google Automatic Alts?

for

From: John Foliot
Date: Nov 19, 2014 12:43PM

Jared Smith wrote:
>
> It looks like it may work quite well for generating a *description* of
> images. But a description of what an image looks like is most often NOT
> a very good alternative text for the image.

A huge +1 for that.

As I noted yesterday
(https://www.facebook.com/johnfoliot/posts/10152873832544784?pnref=story)
what they are producing is actually closer to @longdesc than it is to @alt
(but of course very few will split that particular pedantic hair). We might
also consider using that output with aria-describedby, or the
not-quite-ready-for-primetime aria-describedat
(https://dvcs.w3.org/hg/aria-unofficial/raw-file/tip/describedat.html)


I will continue for the next short while however to beat the drum about
understanding the difference in the ARIA mapping to Accessibility APIs
specification (http://www.w3.org/WAI/PF/aria-implementation/#mapping)
between an "accessible name" and an "accessible description", which as their
names suggest are different ideas altogether:

Accessible name: John Foliot
Accessible description: always wears a cowboy hat, and has a long
moustache

For images, the mappings are:

Accessible name: can be one of @alt, @label, @labeledby
Accessible description: can be one of @longdesc, @aria-describedby,
@aria-describedat

Due to legacy reasons, and authoring issues, we often find authors using
@alt as a hybrid, where the value of alt="{something}" becomes closer to the
description than the name, and "we've" sort have accepted that in the past,
as *something* is always better than nothing. Authors need to remember as
well however that the alt texts should be as short and succinct as possible,
as the values there (unlike my poor beleaguered @longdesc) are voiced
without user-interaction in screen readers, so a 60 word @alt text will be
cumbersome for many.

JF

PS: If you've never looked at the W3C Mappings document, you should, at
least once. Yes it is traditional, dry, W3C spec language, but it is worth
the 20 minutes or so it would take to read through it once.