W3C home > Mailing lists > Public > public-html@w3.org > May 2008

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

From: Maciej Stachowiak <mjs@apple.com>
Date: Sun, 11 May 2008 16:12:24 -0700
Cc: "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: <642E14C3-A9B4-4BBE-A774-FDCBB5D273A1@apple.com>
To: Steven Faulkner <faulkner.steve@gmail.com>

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

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.


Regards,
Maciej
Received on Sunday, 11 May 2008 23:13:17 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Wednesday, 9 May 2012 00:16:17 GMT