Computer technology has the potential to offer individuals with physical limitations greater levels of independence and increased opportunities for meaningful employment, but this can only be realized when the individual can interact efficiently with the computer. Choosing a cursor control device is particularly important given the growing popularity of direct-manipulation style interfaces. Twenty persons with impaired hand and arm function (as a result of a spinal chord injury) and 10 nondisabled persons performed a target acquisition task with five cursor control devices: a mouse, trackball, cursor keys, joystick, and tablet. Even persons with profound impairment were able to compensate for their disability and operate each device by using minor device modifications and/or unique operating strategies. These modifications and compensation techniques are described. Regardless of the physical skill level of the user, the rank ordering of the five devices with respect to target acquisition time was the same. The mouse, trackball, and tablet provided better performance than the keys, which provided better performance than the joystick. Dragging was particularly problematic for persons with motor control limitations, as was acquiring small targets. The implications of the results for hardware and software design are discussed.
Deriving Cursor Control Device Expectations for the Orion Crew Exploration Vehicle