Countering design exclusion: bridging the gap between usability and accessibility

It is known that many people are being excluded unnecessarily from using products, services and environments that are essential for supporting independence and quality of life. Such exclusion often arises from designers taking inadequate account of the end users functional capabilities when making design decisions. This paper addresses how traditional usability techniques can be extended to include accessibility issues by considering the spread of user functional capabilities across the population. A series of measures for evaluating the level of design exclusion based on those capabilities is also presented.