User-centred accessibility supported by distributed, cumulative authoring

Liddy Nevile, Associate Professor, Department of Computer Science and Computer Engineering, La Trobe University, Melbourne, 3086. Email: liddy@sunriseresearch.org

Keywords

AccessForAll, accessibility, digital resources, user-centred

Abstract

In this paper, we describe a strategy for increasing accessibility by exploiting available technologies to match digital resources to users' individual accessibility needs and preferences. This is achieved just in time for the delivery of resources to users by working with descriptions of users' accessibility needs and preferences and relating them to descriptions of resource accessibility characteristics. This strategy supports cumulative and distributed authoring of accessible components for resources where these are missing, and the reconfiguration of resources with appropriate components for users.

Assembling Web resources in an integrated way for delivery to the user is defined as just-in-time accessibility and can increase the availability of accessible resources. Moreover, compared to resources that are accessible to every potential user, universally accessible resources, these resources are less expensive, easier to develop (in terms of skills required), and developed using more satisfactory practices for authors and publishers. In addition, the provision of accessible content can be improved so significantly by the use of specifications-compliant accessibility tools, adopted by moderately competent computer users with no accessibility training, that it is cheaper and more effective to rely on the technology than yet to be developed high-levels of human expertise.

The new approach involves a shift of responsibility from individual authors to technology and a supporting community. The shift means increasing responsibility in the final provision of resources, and thus, of server software. The servers need to check the resources and possibly arrange for services to manipulate and reassemble them before delivering them. The accessible components need to be suitably described to enable their discovery. The components that constitute the final resources may be distributed. This means there is a need for metadata standards that promote interoperability. Finally, there is a need for descriptions not only of resources but also of user needs and preferences.

The term "accessibility" is easily confused with "access", a term used to describe possession of facilities for accessing the Web or rights to use resources. This kind of access is, of course, crucial to any user who is dependent upon the Web. In this paper, however, we are only concerned about people who, for whatever reason, cannot access Web resources, including services, when they are in possession of facilities that should be adequate.