From the course: EPUB Accessibility Using InDesign

Semantics, ARIA roles, and accessibility - InDesign Tutorial

From the course: EPUB Accessibility Using InDesign

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Semantics, ARIA roles, and accessibility

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- [Instructor] This next section of the course is talking about semantics and ARIA roles. This is where the real heavy lifting of Ebook accessibility is done. What do I mean by semantics? "Structure is the element you use to craft your EPUB content, and semantics is the additional meaning that you layer on top of those structures to better indicate what they represent." That's a quote from Matt Garrish again. Semantics is the blue, green, or yellow stickies that you put on the side of a manuscript to give a flag of extra meaning. So yellow could be for copy editing, orange could be for substantive editing, green could be for type setting, that kind of thing. For users of assistive technology, which rely on an understanding of the underlying markup in order to facilitate navigation, the ARIA role attribute allows more precise meanings to be applied to the generic tags. Sometimes the reading system will use that semantic inflection to prescribe a specific behavior, like pop-up footnotes. More commonly, it will be using it to give a little extra definition to a chunk of content. So this slide shows a sort of blur of content. There's headings and text and side bars, there's a lot going on. And what I want you to see in this slide is a blur of content, but then those colorful tags in the margins, which are giving extra meaning to the content. So a section, a sidebar, a new chapter, a footnote, a subhead. Those are the ARIA roles that are defining those chunks of content that sound like a blur to someone who has a print disability, but the ARIA roles give them a little bit more definition. So when you see that layer of alternate meaning in the content as visualized in this slide, you might begin to see the function and importance of semantics. Non-fiction content, for example, might have several different kinds of asides through the course of a chapter. A sidebar, a table, or footnotes. Labeling them with an ARIA role would help the user of assistive technologies sift through the various kinds of asides, a sifting that would be easier for sited readers to do via formatting. As we've seen already, EPUB type semantics are available from InDesign. You saw this in the chapter covering landmarks for example. They are applied at the object level in the object export options menu, and the full set of rules as defined by the EPUB three specification are built in there. Each piece of EPUB type semantics can be mapped to an ARIA role. ARIA stands for Accessible Rich Internet Applications and is a well-established technology in web development circles. ARIA roles are only available to EPUB 3, another reason to avoid using the EPUB 2 spec. Let's look at some resources for ARIA roles. The Daisy Foundation has something called an Accessible Publishing Knowledge Base, and on that page there is a whole bunch of ARIA role attributes that are used commonly in book content. So if we scroll down we see some of the common semantics, cover, preface, foreword, and we see how they're used. Section, roll equals doc foreword. And then ARIA labeled by, that means the header goes with this section is in something with an ID of HDL 1. Those are connecting those. The preface says a section role equals preface and then ARIA label of preface. These are all very commonly listed here, a whole bunch of them. This is a really good thing to bookmark and to have on the side of your screen at any given time, especially when you're planning EPUB, and planning EPUB type semantics. One thing to be aware of is that EPUB type semantics did not live up to what was planned for it. It was planned in the EPUB 3 spec way back in 2011, when that was finalized, when it was intended that assistive technologies would pick up on EPUB type semantics and use those in a meaningful way. It didn't actually materialize. ARIA roles and ARIA semantics are now reusing them in conjunction with EPUB type semantics to add a little extra accessibility support, because assistive technologies understand ARIA roles, and don't necessarily understand EPUB type attributes. I think a full-sum set of semantics to your content lets users see it from a different kind of structure, allowing a fresh layer of meaning for non-traditional users.

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