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Re: [html4all] Request for review of alt and alt value for authoring or publishing tools

From: Charles McCathieNevile <chaals@opera.com>
Date: Wed, 16 Apr 2008 14:40:18 +0200
To: HTML4All <list@html4all.org>, "Ian Hickson" <ian@hixie.ch>, "Joshue O Connor" <joshue.oconnor@cfit.ie>
Cc: wai-liaison@w3.org, "'Tomas Caspers'" <tomas@tomascaspers.de>, wai-xtech@w3.org, public-html@w3.org
Message-ID: <op.t9petgaowxe0ny@widsith.local>

On Wed, 16 Apr 2008 13:56:28 +0200, Harry Loots <harry.loots@ieee.org>  
wrote:

> On Wed, 16 Apr 2008 11:25:17 +0200, Charles McCathieNevile wrote:
>> (Leaving aside the question of validity and focusing on the effect
>> on  users) I am with Ian here. Adding magic values is likely to mess
>> up  existing workflows from user agents through to authoring tools,
>> system  evaluation tools (the sort of thing that the people who
>> currently really  care about getting tehir HTML right actually use),
>> and even websites  explaining how to write good web pages.
>
> Are we saying that once the tool has been published it can not be  
> changed to allow for changes in the way the code is presented?

Not at all. I am saying that standardising some behaviour other than using  
the absence of an alt attribute to signal that there is no decent text  
alternative provided means that most of today's tools would not be useful  
and would need to be changed. So would most of the tutorial information  
around today.

(If we standardised on alt="" instead then there may be a few tools which  
would suddenly work properl, but would be considered broken today).

>> Leaving out the alt attribute  where you don't know anything about what
>> would be a good value (whether  you are a second-rate tool that
>> never asked, or a lazy or second-rate  author that never bothere to
>> think about the answer - and I really do mean  that to sound at
>> least as judgemental as it does) is the simplest approach  to
>> allowing those who are doing a decent job to improve the web overall.
>
> I cannot agree with this viewpoint:
> we share the viewpoint that where ALT has been provided it is assumed to  
> have been provided with good intentions, ie, to describe the image to
> users who may benefit from ALT. On equal terms with this statement where
> developers deliberately add ALT=" " let's assume for the moment that
> they do so in the understanding that AT will ignore the image and skip
> to next segment of text content.

[modulo minor quibbles about alt not being a description per se, but more  
like a "functionally equivalent text", and this being about more than a  
handful of users or about screenreaders, sure]

> Based on the above development practices, we have two scenarios:
> If ALT is used as described above, users who read or hear the text  
> alternative to the visual content are presented with either the
> ALT description or nothing.

Indeed. Depending on what is most useful.

> In the case where ALT has been ignored due to laziness, ignorance, or  
> whatever other reason, the same group of people described above may
> benefit if the UA announces or inserts text to the effect
> 'ALT missing/omitted/not supplied/AWOL' or whatever words we choose
> to tell the user the developer is lazy, second rate or simply
> ignorant of their needs. If the words 'ALT not supplied/whatever' is
> heard/appears, the user knows that an image appeared in the content;
> they do not know if it has value, but at least they can ask
> someone who can view or see the image if it contains information of  
> relevance.

Right.

> If ALT="" is used for this scenario then the user will not know there is  
> an image and will not be able to do anything about it.

Then we really do agree. By *leaving out* the alt attribute, I mean no  
attribute is present. Unless some useful alt content has been supplied,  
there should be no alt attribute and nothing there. This has been a common  
idea in accessibility for something like a decade.

Note that while alt="" and alt=" " are, to a screen reader, equivalent -  
nothing gets read (unless the user has selected super-critical punctuation  
sensitivity), they are different to a visual user with images off, since  
they potentially change the presentation. They are potentially different  
to a braille reader for the same reason. Search engines, software  
evaluation frameworks, and other non-visual user agents may also react to  
them in different ways.

cheers

Chaals

-- 
Charles McCathieNevile  Opera Software, Standards Group
     je parle français -- hablo español -- jeg lærer norsk
http://my.opera.com/chaals   Try Opera 9.5: http://snapshot.opera.com
Received on Wednesday, 16 April 2008 12:43:17 GMT

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