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Re: [html4all] HTML5 Alternative Text, and Authoring Tools

From: Al Gilman <Alfred.S.Gilman@IEEE.org>
Date: Sat, 3 May 2008 15:43:59 -0400
Message-Id: <D9AA8155-3509-48B0-BE33-2095F0B2D33F@IEEE.org>
Cc: Julian Reschke <julian.reschke@gmx.de>, James Graham <jg307@cam.ac.uk>, Steven Faulkner <faulkner.steve@gmail.com>, Ian Hickson <ian@hixie.ch>, John Foliot <foliot@wats.ca>, HTML4All <list@html4all.org>, public-html@w3.org, W3C WAI-XTECH <wai-xtech@w3.org>
To: Henri Sivonen <hsivonen@iki.fi>


On 3 May 2008, at 5:37 AM, Henri Sivonen wrote:

>
> On May 2, 2008, at 17:42 , Julian Reschke wrote:
>
>> In doubt, the default should be not to change HTML4.
>
>
> FWIW, I have a different view of what to do when in doubt:
>
> When in doubt, do what doesn't cause harm.
>
> I think experience (yes, not written down quantitatively) with  
> HTML4 validation shows that casting an *accessibility* requirement  
> into a simplistic presence/absence *syntax* requirement does both  
> good (reminds some people to provide useful alt who somehow  
> wouldn't otherwise) and harm (induces people to pollute non- 
> graphical presentation with duplicate data, useless data like  
> "image" or make the context less understandable by concealing the  
> presence of images).

Can you take the following re-statements as a 'yes'?

> Syntactic presence of @alt on <img> is not a sufficient technique  
> for meeting
> WCAG 2.0 Success Criterion 1.1.1.


> Approximating the accessibility requirements for a text alternate  
> with a syntactic
> requirement for @alt to be present can lead to erroneous practice.


> I believe the current design in HTML 5 and Validator.nu's Image  
> Report feature will pretty much remove the bad effects of requiring  
> alt for validation.

Two ideas:

1) Are you suggesting that HTML5 adopt some sort of a requirement or  
other
endorsement of Validator.nu's Image Report feature?  This is expressly
excluded from the job of a conformance checker in the current TR draft
of HTML5.

http://www.w3.org/TR/html5/#conformance

2) It would seem to me that the value added by Validator.nu's Image  
Report
feature is insensitive to whether @alt is required or not required.
It reduces the criticality of the question, but does not bias the answer
one way or the other.

> Thus, if we consider some kind of indifferent zero level of  
> aggregate goodness/badness, it removes the negative side, so other  
> things can only leave the aggregate positive or to the zero level.
>
> In all likelihood, it will also lop off *some* of the good effects.  
> Still, it seems totally implausible that people who provide alt  
> because they care about accessibility would suddenly stop if it  
> weren't a machine-checkable *syntax* requirement. Hence, it seems  
> plausible that the aggregate effect will remain on the positive side.

You are leaving out the authors who don't care about accessibility  
before
they are nagged, but yet do the right thing when nagged.

Not everyone who discovers @alt via a conformance check stuffs  
garbage in the
attribute.

> Taking a course of action that has both good and bad effects on top  
> of a net-positive aggregate baseline means seeking to do some good  
> while accepting collateral damage of the bad side. I think a course  
> of action with collateral damage should be based on data about the  
> aggregate delta effect of the course of action remaining positive.
>
> We don't have data about that, so defaulting to removing the  
> negative side without knowing the magnitude of either makes sense.

Except that your argument that we are removing only negative is  
debatable,
not prima_facie convincing.

What seems to be broadly agreeable is that Validator.nu's Image  
Report adds significant
value to the authoring process.  But the HTML5 draft currently  
disowns this value.

Al

> -- 
> Henri Sivonen
> hsivonen@iki.fi
> http://hsivonen.iki.fi/
>
>
>
Received on Saturday, 3 May 2008 19:44:45 UTC

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