W3C home > Mailing lists > Public > public-html@w3.org > August 2012

Re: img@relaxed CP [was: CfC: Close ISSUE-206: meta-generator by Amicable Resolution]

From: Michael[tm] Smith <mike@w3.org>
Date: Wed, 8 Aug 2012 00:49:41 +0900
To: Leonard Rosenthol <lrosenth@adobe.com>
Cc: Sam Ruby <rubys@intertwingly.net>, "public-html@w3.org" <public-html@w3.org>
Message-ID: <20120807154939.GA68105@sideshowbarker>
Leonard Rosenthol <lrosenth@adobe.com>, 2012-08-05 09:21 -0700:

> [...]
> So if I were to simply say that HTML should work in the same way, I would
> suggest that the alt element be optional in HTML - so that it's absence
> would not be considered invalid/error by a validator in normal operation.
> However, I would certainly think that a validator that is doing WCAG
> compliance or had an option for "accessibility checking" would certain
> (at least) warn or even error in the case of a missing Alt.

I think part of the problem we are facing with this issue is that some
people are expecting the markup validator to be both a markup validator and
an accessibility checker. I think one way we could address that is, we
could add a prominent link in the post-validation results page for the
validator saying, "You should also check your documents using the W3C
Accessibility Checker", with a link to that checker.

But we don't have a W3C Accessibility Checker. And while I'm aware that
there are some third-party sites that provide accessibility-checking
services, I am not familiar enough with any of them to be confident about
endorsing any by linking to them directly. For one thing, all the ones that
I've seen are only capable of doing WCAG 1.0 checking. I'm not aware of any
that are capable of doing WCAG 2.0 checking. And that spec went to Rec more
than three years ago.

Anyway, although the Nu markup validator has some features (such as the
Image Report feature) that attempt to help with accessibility checking, the
it does not attempt to be an accessibility checker. It really is more like
a linter than anything else, and the design philosophy behind it has always
been to focus on enabling users to find problems in their content that they
might otherwise have overlooked -- problems they want to be informed about.

Having a linter inform users about problems they don't want to be informed
about should be a non-goal. And to the extent that there are scenarios
where users are using the validator to check content which contains
problems they can't fix, it's desirable to not force errors on them for
those cases. And to the extent that forcing errors on them in such a way as
to end up causing someone to decide to make the errors disappear by doing
something that causes documents to be less usable instead of more usable,
that's obviously counterproductive.

So anyway, I think we already have strong agreement that the alt attribute
should be mandatory, not optional, for the majority of cases, but that
there are some exceptions -- for example, for images that are in captioned
figures. For the other particular exception we've been discussing here --
the case of images in HTML content that's machine-generated through batch
processing or whatnot, it seems like we have some general agreement that
it would be useful to add a new attribute to handle if -- *if* we can
manage to figure out how to deal with it in the right way on the validation
+ online accessibility checking side.

But part of the problem is what I mentioned early -- as far as I can see,
there really is no online accessibility checking part that we can rely on
for help with this, so it seems like there is some expectation that we make
up for the deficiency by handling it all in the markup validator.


Michael[tm] Smith http://people.w3.org/mike
Received on Tuesday, 7 August 2012 15:49:50 UTC

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