role=math feedback/questions

> The math role is used to indicate sections that represent math. Such  
> sections SHOULD use a formal mathematical language such as MathML to  
> express mathematical concepts.
>
This requirement makes no sense. The intrinsic semantics of MathML  
already clearly flag any MathML content as being math, so requiring  
role=math also would be pointless and against the stated principles of  
ARIA.
> However, since there exists significant amounts of legacy content  
> that use images and ASCII art to represent mathematical expressions,  
> the math role also allows assistive technology to deliver to the  
> user the text equivalent provided for the image, which can be  
> converted, for example, to Braille or text to speech. The text  
> equivalent used in such situations SHOULD be valid MathML or TeX.
>
Wouldn't putting MathML in alt of an <img> result in a bad user  
experience for users of old AT?

Is AT supposed to implement MathML and TeX support? Have AT vendors  
indicated that they'd do this?

How should the AT decide if the content should be interpreted as  
MathML or TeX? Please define the sniffing algorithm.

What TeX macros should be available implicitly? Please define this in  
detail.

How do you plan on assessing whether there exists two interoperable  
implementations of this feature? (Surely this feature will be dropped  
before REC if two interoperable implementations don't exist?)
> In order to be perceivable, images SHOULD also be labeled by text  
> that describes the math formula as it should be spoken, using the  
> aria-describedby attribute. The text description should have no  
> special markup used to control a speech device.
>
Isn't it an overkill to require both MathML/TeX as 'text equivalent'  
and the reading of the math as words as a textual description?

On the other hand, if the reading of the math as words were put in the  
'text equivalent', wouldn't it be unnecessary to also flag content as  
role=math, since the reading of e.g. the alt of an image would give  
the reading of the math?

-- 
Henri Sivonen
hsivonen@iki.fi
http://hsivonen.iki.fi/

Received on Thursday, 21 May 2009 10:23:39 UTC