[a11y] comments on the navigation requirements

Hi a11y TF,

Following yesterday's call, here are my comments on the "Description of Accessibility Requirements for WP" wiki document, before we share to a larger audience.

The following comments were mentioned in the call, I re-state them here for completeness:

- I find that "accessible to readers" and "machine readable" (used in several places) are a bit confusing. Especially "accessible to readers": does it mean accessible in a browser, or in a WP-aware reading system, or something else?
My suggestion is to see if we can use instead the concept of "accessibility supported", which is well-defined in WCAG.

- the sentence "The information about hierarchy of sections must be preserved in WP" is not very clear to me. As suggested by Matt, one requirement is that "WP needs to define a way to express hierarchical content in a sequence of documents". I also agree with George that the issue isn't just about accessibility, but is a larger one: what does it mean for a document to be part of a web publication? is there an API to see the publication as a whole? etc.

The next comments are about the "navigation and default reading order" section:

- what is meant by "navigation" in this section? does it mean "linked in the ToC" or can it include the other various ways to reach content in a publication (e.g. from list of pages, from a site map, from next/previous links, etc).

- The first bullet says:
> Ideally navigation to all content resources is required, but there can be some flexibility in some situations.

what are these situations ? the current wording is not very precise, so as-is it can (and will) be interpreted as "navigation to all content resources is not required".

We might come up with rules like "if a document has a heading, it must be linked from the ToC", but it would be an a11y guideline rather than something defined in the spec.

> If there is default reading order which lists all the content resources then author can be given flexibility to exclude some content resources from navigation.

This requirement doesn't add much from the previous bullet, which already said that some content resources could be excluded. Is it meant to be a refinement of the first?
Does it mean
- "If the default reading order lists all the content resources, the ToC is optional"?
- OR "If a content resource is in the default reading order, it doesn't have to be linked in the ToC"?
- OR "if a content resource can be accessed in a natural reading order, if doesn't have to be linked in the ToC"?
- OR something else?

> If default reading order does not cover all content resources (e.g. decision tree based traversal in publication) then access to all the content resources has to be ensured with navigation.

That's interesting: let's consider a publication with most of its content outside the default reading order (e.g."chose your own adventure").
Does all the content need to be *directly* accessible from a top-level navigation, or is it enough to be somehow reachable from *a* natural reading order?
(Note: I'm using "natural reading order" to describe a reading order that is a natural reading sequence, if not the default one.)
There's also the author's intent, who might want to hide some content until some reading is done. Wouldn't that be in conflict with this requirement?

> For the resources in default reading order, continuous reading experience is required. In other words, the user should be able to move from end of a content resource to the next resource without going through TOC again.

Good. Here particularly, using "accessibility supported" may free us of the "browser vs. RS" debate.

> In all the above scenarios, user agent should be able to inform users about their current reading location in WP.

This is SC 2.4.7., plain and simple. We should say if there's anything specific to WP here.

Thoughts welcome!
Romain.

Received on Thursday, 7 September 2017 08:32:03 UTC