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

From: Ian Hickson <ian@hixie.ch>
Date: Tue, 15 Apr 2008 21:56:36 +0000 (UTC)
To: Joshue O Connor <joshue.oconnor@cfit.ie>
Cc: John Foliot <foliot@wats.ca>, 'Tomas Caspers' <tomas@tomascaspers.de>, wai-xtech@w3.org, wai-liaison@w3.org, public-html@w3.org, 'HTML4All' <list@html4all.org>
Message-ID: <Pine.LNX.4.62.0804152153310.29828@hixie.dreamhostps.com>

On Tue, 15 Apr 2008, Joshue O Connor wrote:
> Ian Hickson wrote:
> > There is *absolutely no practical difference* to the UA between 
> > omitting the alt="" attribute altogether, and having the alt="" 
> > attribute set to some magical reserved value. They are functionally 
> > identical, and user agents can get as much information from either.
> 
> Thats not entirely true. If you consider a UA like a screen reader which 
> will pretty much by default skip images that have a null alt value and 
> the other situation you cite where there is some reserved value that 
> will potentially trigger some kind of behaviour (which is undefined as 
> yet). The difference (an benefit) of this magical reserved value is that 
> the user may be able to choose to also ignore it via some verbosity 
> settings. Without this 'magical reserved value' the screen reader will 
> potentially default into heuristic evaluation which is not desirable 
> when interacting with an application - such as the much vaunted photo 
> sharing application - and its dynamically generated/random alphanumeric 
> URLs. [1]

I don't understand. Why can't whatever behaviour will happen for 
alt="magic vlaue" also happen when the alt="" attribute isn't present? In 
both cases we're talking about future tools, and in both cases we're 
presumably talking about the same behaviour. I agree that the users of 
legacy tools are screwed either way (magic value or missing attribute, 
both will result in a poor user experience for these images in today's 
UAs, though the missing alt case at least typically has user prefs so that 
the user can tweak those cases, another reason why I personally prefer 
simply omitting the alt="" attribute rather than introducing keywords).

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'
Received on Tuesday, 15 April 2008 21:57:26 GMT

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