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Re: HTML Action Item 54 - ...draft text for HTML 5 spec to require producers/authors to include @alt on img elements.

From: Robert J Burns <rob@robburns.com>
Date: Mon, 12 May 2008 09:47:14 +0000
Cc: Steven Faulkner <faulkner.steve@gmail.com>, "public-html@w3.org" <public-html@w3.org>, W3C WAI-XTECH <wai-xtech@w3.org>, wai-liaison@w3.org, Dan Connolly <connolly@w3.org>, Chris Wilson <Chris.Wilson@microsoft.com>, "Michael(tm) Smith" <mike@w3.org>
Message-Id: <082367F5-2935-466E-8241-8EDE4235F362@robburns.com>
To: Maciej Stachowiak <mjs@apple.com>
Hi Maciej,

On May 11, 2008, at 11:12 PM, Maciej Stachowiak wrote:

>
> Hi Steve,
>
> On May 8, 2008, at 8:28 AM, Steven Faulkner wrote:
>>
>> Dear HTML WG members,
>>
>> The first draft of our rewrite of major sections of 3.12.2 "The img
>> element" in the HTML5 draft is now available:
>>
>> http://www.paciellogroup.com/blog/misc/uc/
>
> Thanks for writing up a proposal. This proposal does not cover the  
> use case where HTML generated by a tool does not have a textual  
> alternative available. Examples include:
>
> - Dragging a photo into a WYSIWYG mail program's composer (Mail  
> programs do not normally prompt for a description and doing so would  
> be confusing to users)
> - Bulk upload of photographs to a photo sharing site, where the  
> photographer is unwilling to put in the effort to individually  
> describe each one
> - A script that scrapes images from other sources that lack text  
> alternatives, and generate html

Keep in mind that the use cases you list here are due to trying to  
make the alt attribute more than it currently is in HTML4 and  
according to best practices. The second two items should be alt=''  
according to this proposed re-draft. For email too, the use of alt=''  
would almost always be the appropriate attribute value. Only in the  
case where someone is writing a very, very long email or doing very  
fancy things with text or images in the email would this proposed  
section require anything other than alt=''. And under those  
circumstances I don't see why we should expect anything less from an  
emailed document than one delivered via http.

In the case of bulk upload, the authoring tool only needs the actual  
titles of the photographs (however authored) and requires no other  
information from the author to be conforming under the proposed new  
section.

> These would all be covered by "Images of Pictures" but the required  
> description is not available. Thus, the proposal does not cover all  
> the use cases handled by the current spec language.
>
>
>
> It also requires redundant text in many cases where the current spec  
> would call for empty alt. For example:
> <p id="piedescription">According to a study covering several billion  
> pages, about 62% of documents on the Web in 2007 triggered the  
> Quirks rendering mode of Web browsers, about 30% triggered the  
> Almost Standards mode, and about 9% triggered the Standards mode.</p>
> <p><img src="rendering-mode-pie-chart.png" alt="The majority of  
> documents triggered quirksmode." aria-describedby="piedescription"></ 
> p>
>
> Is there any reason to believe that redundant text description of an  
> image that recapitulates the text is helpful, rather than harmful,  
> to users who use textual alternatives? After all, "The majority of  
> documents triggered quirksmode" is just a restatement of "62% of  
> documents on the Web in 2007 triggered the Quirks rendering mode of  
> Web browsers". Furthermore, aria-describedby would link the image to  
> a long description, thus possibly leading the screen reader user to  
> hear the same information yet a third time.
>
> Is there reason to believe that screen reader users like to hear  
> things two or three times? I have not done any studies but this is  
> surprising to my intuition. I would have concluded that using alt=""  
> to present the screen reader user (or other users of aural or text- 
> only media) with the information only once is best. It may be that  
> this surprising conclusion is correct but I would like to hear some  
> justification.
>

If you take a closer look at the proposed language, it explicitly  
advises authors to not include redundant text but instead use alt=''  
where the value would otherwise be redundant.

Take care,
Rob
Received on Monday, 12 May 2008 09:48:52 UTC

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