2013-06-08 0:13, Ian Hickson wrote:
On Sun, 2 Jun 2013, Jukka K. Korpela wrote:
The purpose presented is "to avoid markup generators from being
pressured into replacing the error of omitting the alt attribute with
the even more egregious error of providing phony alternative text". This
is rather speculative, and it seems to lead to various attempts that are
more or less self-contradictory.
It's not that speculative, your e-mail is a response to a markup generator
implementor who feels pressured in exactly this way!
And who wrote that generator-unable-to-provide-required-alt is...
inadequate.
Authors of generators always have the option of generating things like
alt="(an image)", which can hardly be worse than lack of alt attribute.
It's worse because it prevents authors from being able to find images that
are lacking good alternative text, and because it makes it less likely
that future user agents will try to automatically figure out what the
alternative text should be (since one is already provided).
To a user, even “(an image)” is better than lack of alt attribute, which
is what generator-unable-to-provide-required-alt really means. And in
the case of user-submitted images, “(a user-submitted image)” might be
even better. Lack of alt can mean just about anything; there are
millions if not billions of images without alt attribute just because an
author did not think of the issue. A generic text “(an image)” at least
suggests that it’s a content image with no obvious alternate text.
To analyze which images lack good alternative texts, you need to look at
the images in their context. It’s just wrong to assume that they can be
identified using some simple automated analysis. And future user agents
won’t try to figure out what the alternative text should be, any more
than current browsers do such things. It is just wishful thinking to
expect such processing, and if browsers tried to do such things, they
would just mess things up.
Yucca
