24.8.2011 23:50, Clint Goss wrote:
ARIA does seem to be a comprehensive proposal for accessibility.
It is specifically about accessibility (not about the idea of providing
alternative presentations in general), it is complex, it is meant for
specialized user agents and assistive software (as opposite to
mainstream browsers in normal use, the use that most authors and
developers focus on), and it is difficult to test.
So I'm afraid it will be used by a small minority of authors and
developers only.
The need for "alternate text" should be much easier to recognize, and it
a simple solution is available and works, it could be used when the need
is obvious and the solution helps.
My concern with all this is more social engineering than definition. I
think the practicalities of nudging web authors into supporting blind
and limited-sight viewers are daunting. It’s hard enough to get authors
to include @alt for images
Indeed.
(although I was not able to quickly find
stats on compliance of the mandatory @alt).
One might measure the compliance to the formal requirement of having an
alt attribute for every <img>. But this would give much too high
figures, since it is so common to have alt attributes that are useless
or worse, failing to comply with the requirement that the attribute
specify a textual replacement for the image.
But _many_ authors _often_ use alt attributes in a useful way, and this
helps people. On similar grounds, it would be useful to have a simple
way of specifying textual replacement for text. But the problem is how
to define the markup and how to define the conditions for using the
textual replacement.
In some use cases, it would suffice to define as follows: an alt
attribute on a <span> element or other phrase element indicates the text
to be used in place of the element content, if the content cannot be
presented as graphic characters; for example:
<span alt="diameter">⌀</span>
or
<span alt="ø">⌀</span>
(A browser would be expected to use the alt fallback if it cannot render
the content as the diameter sign, probably due to lack of such character
in available fonts. And maybe the idea could be extended to rendering
content non-visually; in that case, only the former fallback would make
sense.)
--
Yucca, http://www.cs.tut.fi/~jkorpela/
