W3C home > Mailing lists > Public > www-style@w3.org > June 2011

Re: [css3-speech] tables and speak-header

From: Daniel Weck <daniel.weck@gmail.com>
Date: Thu, 16 Jun 2011 09:28:41 +0100
Cc: www style <www-style@w3.org>
Message-Id: <345930B7-6F5E-46DC-B093-070655463EAC@gmail.com>
To: Andrew Thompson <lordpixel@mac.com>
Thanks for your detailed reply Andrew :)
Cheers, Dan

On 16 Jun 2011, at 04:40, Andrew Thompson wrote:

> On Jun 15, 2011, at 6:38 AM, Daniel Weck <daniel.weck@gmail.com>  
> wrote:
>> Also see this short discussion thread (December 2010):
>> http://lists.w3.org/Archives/Public/www-style/2010Dec/0235.html
>> http://lists.w3.org/Archives/Public/www-style/2010Dec/0240.html
> Yes, sorry, I missed that.
>> The problem with the 'speak-header' property (as defined by the CSS  
>> 2.1 Aural Stylesheets Appendix) is that it only _partially_  
>> addresses a broader *usability* issue. User-agents that support  
>> aural rendering of (potentially-) complex tables normally ensure  
>> that users can navigate within the non-linear structured playback  
>> stream (beyond simple play/pause), and let the user configure the  
>> navigation controls (row-first, column-first, headers-first, etc.)  
>> as well as the verbosity of the aural feedback. Such feedback may  
>> consist in audio icons, as well as speech synthesis used to render  
>> cell metadata (column/row header text, indices, vertical/horizontal  
>> cell span, etc.).
>> This flexibility yields a number of possible combinations, i.e.  
>> different ways a user may wish to navigate data, based on personal  
>> ability, preferences, etc. In fact, the same person may start  
>> reading a document with full verbosity, to finally end-up  
>> navigating the document with fewer structural cues (either because  
>> that person quickly trains-as-he/she-reads, or because the low  
>> complexity of the encountered table data doesn't justify the use of  
>> high verbosity, for example).
>> So to a great extent, the 'speak-header' property is the tip of an  
>> iceberg that represents use-cases which authors should not really  
>> be concerned with. Content authors should primarily ensure that the  
>> markup data is well-structured and semantically-rich, and may  
>> choose to insert supplementary audio cues (pre-recorded icons or  
>> generated TTS) via their speech-specific styles. I don't think that  
>> authors should dictate the user-experience in the case of tables  
>> (we recently came to the same conclusion with regards to announcing  
>> the nesting depth of list items)
>> So, this issue is effectively better solved at the user-agent  
>> level, and this is why I decided not to object to the historical  
>> decision not to include the 'speak-header' property in CSS3 Speech  
>> Module.
>> Thoughts welcome :)
>> (by the way, is your aural CSS implementation available publicly?)
> The recent list discussion prompted my email, since logically if  
> you're going to say something about lists, even at the level of 'the  
> UA SHOULD' then is it consistent to be completely silent on tables?
> That said, I agree that the majority of the author's responsibility  
> falls on using the underlying markup language's semantic  
> capabilities to produce a well structured table. And how the UA  
> renders tables is for the UA to define in conjunction with user  
> preferences. The role of CSS should be to allow the author to give  
> the UA hints about presentation that it could not otherwise  
> determine by inspecting the markup. Simple stuff such as suppressing  
> a <caption> is obviously well covered by selectors and CSS3 Speech.  
> And hence I suppose the beautifully constructed table example in the  
> 2.1 spec (http://www.w3.org/TR/CSS21/aural.html#aural-tables) which  
> illustrates a case where selectors are not enough; speak-header  
> would be required if the AUTHOR is to control how often the headers  
> are repeated. But your point is that really most of these kinds of  
> presentation choices should be up to the UAs defaults and the user's  
> preferences, NOT the author.
> The remaining question would be, what about user style sheets?  
> Clearly a UA could build custom UI for all kinds of preferences and  
> settings, or they could allow a user stylesheet as a way to override  
> the defaults. But your use case above above about adjusting the  
> verbosity in the _middle of reading a document_ reveals what a poor  
> solution user style sheets would be.
> In short, I'm convinced that CSS3 should not try to describe this.
> As for my 'aural css' implementation, that would be a very generous  
> description. What I built at the time was a very basic web browser  
> that rendered HTML into speech and allowed keyboard navigation via a  
> cursor. Think lynx except nowhere near as complete.  Towards the end  
> of the project I had a week or so to spare so I layered on some  
> basic support for CSS aural properties, but it was mostly an after  
> thought.
> Coupled with the fact it required Mac OS 9 (!) and Java 1.1 to run,  
> I don't think it would even be worthy of curiosity at this point.  
> Things have moved on!
> Thanks,
> AndyT

Daniel Weck
Received on Thursday, 16 June 2011 08:29:20 UTC

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