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Re: Stephen Ferg's Table Research

From: Ian Hickson <ian@hixie.ch>
Date: Tue, 14 Aug 2007 07:42:05 +0000 (UTC)
To: Jason White <jason@jasonjgw.net>
Cc: HTMLWG <public-html@w3.org>
Message-ID: <Pine.LNX.4.64.0708140721560.21877@dhalsim.dreamhost.com>

On Tue, 14 Aug 2007, Jason White wrote:
>
> The assumption that most authors won't add markup to assist non-visual user
> agents and assistive technologies is also not a good starting point from which
> to discuss accessibility.

(The following isn't intended to make any judgements on the various
proposals for how to handle associating header cells with data cells in
tables. I'm just discussing language design at an abstract level here.)

There are two concerns with regard to specialised markup such as markup 
intended for non-visual user agents. The first is that most authors won't 
necessarily use the markup at all. That's not a huge problem, though of 
course it is a disadvantage of such solutions and should be taken into 
account (in particular, all other things being equal, if two solutions 
differ only in that one will get used by authors even when they don't 
think of users with unusual setups but the other won't, then the former is 
likely better).

The second is that authors will misuse the markup. This is a much, much 
larger, and very real, problem. If markup is misused more than it is used 
correctly, especially if the misuse is indistinguishable from correct use 
from a computer's point of view, then the feature can in fact end up 
making the user experience _worse_ for users in ususual configurations 
than the absense of any feature at all.

An example of this would be the usemap="" attribute on <input> elements. I 
recently decided to not supports this attribute on <input> elements in 
HTML5, after having done a thorough study which discovered that in almost 
all cases, pages that used the usemap="" attribute on <input> elements 
actually behaved better in user agents that did not support that attribute 
than in user agents that _did_ support it. [1]

It's sadly the case that most features that don't have an effect in the 
most common configuration (the configuration most often tested by authors) 
end up abused like this, which is a very strong reason to avoid this kind 
of feature when designing the language.

Having said that, it's not always bad. The alt="" attribute, for instance, 
is used widely, and is used correctly in a significant fraction of cases. 
That's why we have to examine each case individually, and is why research 
into how features are actually used is so important.


-- Footnotes --
[1] This was a thread in which I was dealing with feedback sent to the 
WHATWG list some time ago. The e-mail in which I detail the study is here: 
http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2007-August/012334.html

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'
Received on Tuesday, 14 August 2007 07:49:22 GMT

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