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Accessibility of XR - Notes on the Framework for Accessible Specification of Technologies

From: White, Jason J <jjwhite@ets.org>
Date: Wed, 27 Mar 2019 19:24:41 +0000
To: "public-rqtf@w3.org" <public-rqtf@w3.org>
Message-ID: <BN7PR07MB4849C76F566784997E2E9151AB580@BN7PR07MB4849.namprd07.prod.outlook.com>
I reviewed the Framework for Accessible Specification of Technologies (FAST)<https://w3c.github.io/apa/fast/> in connection with the accessibility of applications that are on the reality/virtuality continuum. These include virtual reality and augmented reality scenarios. Any technologies developed to standardize the creation of XR applications are clearly candidates for use of the strategies documented in the FAST. The user needs identified therein are also strongly relevant.
Many of the user needs identified in the FAST are pertinent to XR technologies, as are the approaches put forward for addressing them. Nevertheless, there are some issues emerging from the XR-related literature that we have reviewed which are not currently represented in the user needs or associated technical design strategies, according to my reading of the FAST document.
Significantly, these issues can however be located (sometimes, admittedly, by stretching the principles) within the conceptual framework provided by functional performance requirements as articulated in accessibility policy standards, notably the section 508/section 255 standards in the U.S., and EN 301 549 in the E.U. See, for example, EN 301 549, clause 4<http://mandate376.standards.eu/standard/functional-statements>.
It should be noted that the functional performance requirements need to be applied not only individually, but also in combinations in order to capture the diversity of users' needs and capabilities.
Examples of XR Accessibility Issues Addressed by Functional Performance Requirements
It was noted in APA Working Group discussions that some XR environments make assumptions about the user's ability to reach the controls provided by the user interface, including the ability to turn around in order to reach certain controls. Clause 4.2.8 ("Usage with limited reach") addresses this concern, although it is stated to apply to cases in which "ICT products are free-standing or installed" - not precisely the XR scenarios that we have in mind, but very close, and articulating the correct requirement.
The specific issue of captions in 360-degree video resides under clauses 4.2.4 and 4.2.5 (note the cross-reference in the latter section).
The problem, identified in the literature, of providing nonvisual descriptions of a virtual scene without overwhelming the user with information concerning all of the virtual objects in the vicinity, is not so easily classified. It appears to me to derive from elements of 4.2.1 ("Usage without vision") and 4.2.10 ("Usage with limited cognition"). The cognitive limitations are not in this case necessarily due to learning or cognitive disability, but rather to the cognitive demands of dealing with extensive information about a visual scene delivered in a serial (textual) communication channel.
A challenge for screen reader users, identified in the literature, of walking to a particular object in the virtual environment, or of following another participant, presumably lies under 4.2.1 ("Usage without vision"). The solution is to provide commands for performing these functions. I suspect similar issues could arise for those with "limited manipulation or strength" (4.2.7).
Considerations for Further FAST Development
Functional performance criteria, individually and in combination, could serve as a useful conceptual tool with which to identify and understand accessibility challenges emerging from actual or proposed new technologies. They could also serve as organizing principles for understanding users' access needs. I think consideration should be given to how to integrate them appropriately into the FAST. In addition, there are some XR-specific user requirements that could be included, or given as examples in the document.

Comments are most welcome.




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Received on Wednesday, 27 March 2019 19:25:08 UTC

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