Satisfying Divergent Needs in User-Centered Computing: Accounting for Varied Levels of Visual Function

Abstract

The ubiquity of information technologies imposes serious and debilitating limitations on people whose abilities fall outside the range of what is generally considered normal. Those at all ages who experience perceptual, physical, and/or cognitive impairments often have diminished functional abilities, and thus, their technology interaction requirements are often unmet by mainstream technologies. In this chapter, we describe an approach to the advancement of baseline human-centered computing for all users, as well as a summary of advancements championed by research, industry, and government initiatives. These efforts have generated a need for a measured, scientific method to unify accessibility design approaches that can be applied in practice. A user's functional abilities serve as the foundation for this framework on which the design process can evolve. Methods for deriving user needs and establishing thresholds for performance are described in the context of human-computer interactions by users with visual impairment. This framework provides the basis for users who have limited functional abilities to claim or reclaim access to information technologies, sustain or regain independence in their lives, and take full advantage of the opportunities that information technologies afford.