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Re: Investigating the proposed alt attribute recommendations in HTML 5

From: Leif Halvard Silli <lhs@malform.no>
Date: Thu, 30 Aug 2007 01:45:56 +0200
Message-ID: <ca6e31ee5b07049c795b58ac0846b086@10013.local>
To: Maciej Stachowiak <mjs@apple.com>
Cc: HTMLWG <public-html@w3.org>, wai-xtech@w3.org, Steven Faulkner <faulkner.steve@gmail.com>

2007-08-30 00:03:17 +0200 Maciej Stachowiak <mjs@apple.com> wrote:
> On Aug 29, 2007, at 11:48 AM, Steven Faulkner wrote:

>> Investigating the proposed alt attribute recommendations in HTML 5 - 
>> http://www.paciellogroup.com/resources/articles/altinhtml5.html
> 
> It looks like the flickr page 

[ Located at <http://www.flickr.com/photos/tags/sleepingcats/> ]

> you tested is a search, which doesn't  include 
> the title or caption.

This is not true. Here is an analysis of this page and the alternative page you proposed to test.

The above page include TITLE= on the images. Howver, I suppose what you meant to say is that the Title= attribte isn't in the IMG element itself, but only the surrounding A-element.  However, «If this attribute is omitted from an element, then it implies that the title attribute of the nearest ancestor with a title attribute set is also relevant to this element.» (HTML5 on the use of TITLE= [1])

> What about a page like this (I found it  from the 
> example you used), where the titles are included, and are  duplicated by the 
> alt text:
> 
> http://www.flickr.com/photos/11994078@N04/

That is a questionable test page in this context. Because, if you had read the source better, you would have seen that it involves testing many other things than simply the effect of how one use the ALT attribute:

(1) The IMG tags on that page does not have TITLE=. Instead it has captions.
(2) BUT, the captions are placed inside a H4-element, inside its own TD-cell. Whereas the the image is placed in the TD cell just below this TD-cell, in the same column.
(3) The TD with the IMG does not have a HEADERS= attribute which shows what its caption cell is. I have now clue how the H4-element is linked to the image cell ...

May be the captions should have been in TH-cells ... Or, the best would probably have been if the IMG and the caption was placed in the same cell (if TABLE should be used at all).

> Based on what you said about JAWS, it sounds like alt="" might give  the best 
> results in that version of JAWS.

I don't think so.

If we assume that JAWS can/could establish the relationship between the caption and the image by applying its heuristics, then I think these images could be described as buttons - as they are wrapped in the A-element and because their title is given in the caption. The relavant section in HTML5 is  «Icons: a short phrase or label with an alternative graphical representation» [2]. As there is no other text inside the A-element, the IMG must have alt text. But it should have been only a short button-text.

The ALT could have been empty if the caption had been kept inside the A-element - together with the IMG. Then we could have omitted the alt-text, according to HTML5: «In some cases, the icon is supplemental to a text label conveying the same meaning. In those cases, the alt attribute must be present but must be empty.»

But it also depends on how the page is intended to be read. All images are buttons. But many readers would not be interested in clicking on those "buttons" - they would be content with looking at this page alone. If that is the intention, then the images should have had full replacement texts, which described the content even better than what the captions do.

[1] <http://www.whatwg.org/specs/web-apps/current-work/multipage/section-global.html#title> 
[2] <http://www.whatwg.org/specs/web-apps/current-work/multipage/section-embedded.html#alt>
-- 
leif halvard silli
Received on Wednesday, 29 August 2007 23:46:15 GMT

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