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Epub accessibility testing tips and resources

Posted: Tue Oct 16, 2018 5:36 pm
by Heidi
Good afternoon everyone. I hope all of you are having a great week!
I would just like to share a few EPUB accessibility tips and resources that I have found to be very helpful in my work thus far. I apologize if this information is not new to many of you, but I hope that the resources I have found will be of assistance at some point during your work.
Some books contain media overlays with audio content that can be synchronized with the text. I ascertainhow closely my position within the audio matches with my text location by listening to the audio for 30 seconds, pausing it, then comparing my playback position with my location in the text. If my positions within the text and audio were identical after pausing, I noted this in a text file. I ran about another 10 tests at various points within the book. I then jump to a few different sections within the text, keeping track of how closely audio playback matches my new text locations. If my text and audio positions continued to closely match, I could determine that they were synchronized for a given reader. Daniella has given me an excellent method of quantifying how closely the audio feed matches my current text position. Using a timer or stopwatch can allow you to numerically quantify how closely text and audio are synchronized.

While delving into how EPUB documents are coded and structured, I've come across some great resources online. Laura Grady has written an excellent article:
Ebook Accessibility: Here’s What You Might Be Missing
EPUB Secrets is a goldmine of articles relating to the EPUB file format, EPUB readers and accessibility. The site is updated with new content quite frequently.
The DAISY Consortium's Accessible Publishing Knowledge Base is a place I always turn to if I have any technical questions during the testing process. The knowledge base is a comprehensive guide, providing best practices for creating accessible EPUB books and digital publications.
If you wish to dig into the nuts and bolts of how an EPUB document is put together and coded, I recommend reading
Epub: the Language of ebooks
I hope some of you will find these resources to be helpful. If you have any questions, please do not hesitate to ask. I wish all of you a great day!

Re: Epub accessibility testing tips and resources

Posted: Thu Oct 18, 2018 8:07 am
by Danny
Hey Heidi,

These are awesome resources! Thank you so much for such an informative and helpful post!

Re: Epub accessibility testing tips and resources

Posted: Thu Nov 01, 2018 8:03 am
Hi there,
Thanks for all the resources. A good book that I read a while ago to learn more about EPubs was EPUB 3 Best Practices
Optimize Your Digital Books
By Matt Garrish, Markus Gylling. Even though it came out in 2013, it still provides a lot of relevant information and acts as a good foundation since it gives a great overview of how an Epub is put together and there is certainly a strong section on accessibility.

Page Navigation

Posted: Tue Nov 20, 2018 12:19 pm
by Danny
One of my pet peeves in testing an ePub is page numbering. If a fictional story doesn't contain page numbers, it's not likely to be an issue. But if page markers are included, if all the hard work has been done to denote where each new page starts ... then it should actually work!

So here's what I've found regarding including page number and page navigation.

Beware, even if it is a version 3 ePub, it is common for navigation to be provided solely in toc.ncx. Version 3 guidelines stipulate that toc.xhtml and-or nav.xhtml are supposed to be provided, but I have found this to be rare. In fact, I have yet to come across a book that offers a page list in an xhtml format.

Which brings us to the pageList. Directly after the navpoints in toc.ncx, if page navigation is offered, publishers should include a pageList. Similar to the <Nav> section, the <pageList> section indicates the title of each element, and includes an imbedded resource to jump to it. Here is an example.

<pageTarget type="front" value="006">
<content src="Chapter1.xhtml#pbr-006"/>

You may come across other parameters in the <pageTarget tag, such as id or playOrder, but the presentation style remains the same.

So now we have a list of page navigation. Let's take a look at what happens if the user wants to jump to page 6.

Print page breaks should be marked like this.

(<span epub:type="pagebreak" role="doc-pagebreak" id="pbr-006" title="6" />

Note that the zero's have been stripped from the page number in the text and title elements above. Often publishers will call the page 006 here, which is incorrect. You wouldn't tell someone to go to page 0 0 6 (unless perhaps you were in the army) so the leading zeros should not be included here, either.

It is rare for publishers to mark their page breaks using a <Span> tag. Too often they will indicate them with an anchor (<A>) tag. While this works fine for page navigation, it does not allow the book reader to announce the new page number, if desired.

I spent so long looking for a book with properly-coded page breaks that I wanted to share this for others who may be still searching for one. Please take the above with a grain of salt, and if I've misunderstood something, don't hesitate to point it out. I'm just going by what I've encountered and how readers interpret it - not to mention the UBC accessibility report.