Including users with motor impairments in design

For people with motor impairments, access to, and independent control of, a computer can be an important part of everyday life. However, in order to be of benefit, computer systems must be accessible. Computer use often involves interaction with a graphical user interface (GUI), typically using a keyboard, mouse, and monitor. However, people with motor impairments often have difficulty with accurate control of standard input devices (Trewin & Pain, 1999). Conditions such as cerebral palsy, muscular dystrophy, and spinal injuries can give rise to symptoms such as tremor, spasm, restricted range of motion, and reduced strength. These symptoms may necessitate the use of specialized assistive technologies such as eye-gaze pointing or switch input (Alliance for Technology Access, 2000). At the same time, specialized technologies such as these can be expensive and many people simply prefer to use standard input devices (Edwards, 1995; Vanderheiden, 1985). Those who continue to use standard devices may expend considerable time and effort performing basic actions. The key to developing truly effective means of computer access lies in a user-centered approach (Stephanidis, 2001). This article discusses methods appropriate for working with people with motor impairments to obtain information about their wants and needs, and making that data available to interface designers in usable format