Excluding math types?

[mattgarrish]

Isn't it possible that a book could have mathml and latex equations, or some mathml and some described images?

The rich content output strings start with an if/else if/ else if for the math possibilities, so only one can occur. The same isn't done for the different chemistry types.

Should these be switched so they are all "if" checks?

[mattgarrish]

Reopening as this also occurs in the onix techniques

[gregoriopellegrino]

I remember that describedMath we had mutually-excluded it with MathML, because many GCA titles contain both MathML metadata and describedMath

[mattgarrish]

MathML improves the layout and provides some navigation, but the actual readability of the equations may be poor depending on the device, so I'd think it would be helpful to know if it's also described.

[mattgarrish]

It looks like the output string for described math is a bit misleading. MathML with descriptions is also described math. The output is assuming only images are described.

[clapierre]

GCA originally was encouraging publishers to put into the MathML itself the "alttext" description of the math it represented. In doing that we also recommended that the metadata accessibilityFeature="describedMath" and "MathML" both be present.

However, after one of our calls it was encouraged that this practice be discontinued and that we shouldn't be encouraging publisher to put anything in the MathML's "alttext" and let the ReadingSystem handle how to speak that mathML with its own "Read Aloud" functionality (usually implemented with either MathCAT or MathJAX") as this would provide a better user experience with potentially synchronized highlighting of the math elements.

accessibilityFeature="describedMath" should only be present with an image of math contains an "alt" description of the math equation.

So the only way you would ever have both "MathML" and "describedMath" metadata in the same book is when there is both real MathML equations and images of math with an alt text description provided. (Why you would ever have both is a good question, maybe as a fallback if MathML is not supported, like our test books have both the image of MathML with alt text and below it a Details element containing the real MathML.

This was my understand from our last meeting on this topic.
If this is the case our GCA next Technical Bulletin will also be pointing out this new 'Best Practice' on how to handle math within an EPUB and what metadata should accompany it.

[mattgarrish]

Math is visual media, though. I wouldn't want to tell publishers not to also describe their equations for people who have difficulty reading them (whatever the reason, which could include cognitive disabilities), even if there is MathML markup.

It may not be strictly required to pass WCAG to describe the MathML, but it feels like we're making an assumption for a certain kind of production.

It feels a lot like the fixed layout transformability issue. Are we going too far in overriding what the publisher may be trying to claim?