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[whatwg] Alt text authoring Re: Conformance for Mail clients

From: Charles McCathieNevile <chaals@opera.com>
Date: Mon, 23 Apr 2007 02:16:16 +0200
Message-ID: <op.tq7m1el7wxe0ny@widsith.local>
On Sun, 22 Apr 2007 19:58:13 +0200, Kristof Zelechovski <giecrilj at stegny.2a.pl> wrote:

> For (2): alt="(Your browser does not display graphic images)".

No. Where an alt would be required to makes sense of the image, but is not there, the attribute should simply be left out.

Browsers have handled this error condition the best they can for years, and have various strategies for dealing with it ranging from adding "image" on demand (so users can download it, mail it to someone else, and ask what it is) to doing a complicated lookup on the web or in a local library for a version of the image that has been described.

Putting any kind of default means breaking all backward compatibility with this work, and doesn't offer any improvement to anybody. Making up some standard phrase or adding some new attibute still breaks backward compatibility, still offers no substantive improvement, and involves agreeing on something that experts will argue is counterproductive in the first place.

Where the author has deliberately decided not to have alt (e.g. because the image doesn't add anything important to a text version of the content), alt="" is appropriate. Distinguishing this case from there authors have just not bothered to put anything in (or can't) is an important reason why it is a dreadful default to add.

> -----Original Message-----
> On 4/22/07, Kornel Lesinski <kornel at osiolki.net> wrote:
>> On Sun, 22 Apr 2007 01:26:55 +0100, Jon Barnett <jonbarnett at gmail.com>

>> > By "entirely omitted alt", do you still only mean WYSIWYG editors?  If
>> > not, I agree.  The distinction would be as follows:

>> > (2) <img src="gallery2.jpg">  The image is part of the content and
>> > doesn't represent text.

> If the alt attribute is required, what should it be for (2)?  Blank?
> A paragraph describing the vista of the Grand Canyon?

Without context, this question is more or less impossible to answer in the general case. A useful alternative will give some information about how this image fits into the content of the page, without going into a detailed description. Ideally, that would be linked via longdesc for something like "a sweeping vista of the grand canyon on the rainy winter day that I visited it in 2010, before it had been mostly filled in to provide the carpark that handles the millions of visitors now coming each month to see the exhibition 'what we lost - the empty canyon'". While browser handling of longdesc is almost universally woeful, the only exception I know of being iCab, there are plenty of extensions available, some built into screen readers, that dothe trivially simple job of making the description available.

Options might include "image 2 - vista of the canyon" or "image 2" (where the text already says what that is) or all kinds of other things.

Writing alternative text is an art, not a science. There are parts of the art that are easily explained (although this discussion is a worrying sign that there is currently a disconnect between the people who understand something of the science and some of the people who are planning how the web should develop).

cheers

Chaals

-- 
 Charles McCathieNevile, Opera Software: Standards Group
 hablo espa?ol  -  je parle fran?ais  -  jeg l?rer norsk
chaals at opera.com          Try Opera 9.1     http://opera.com
Received on Sunday, 22 April 2007 17:16:16 UTC

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