ABSTRACT
Spatial display instruments convey information about the identity and the location of objects in order to assist surgeons, astronauts, pilots, blind individuals, and others in identification, remote manipulation, navigation, and obstacle avoidance (Bach-Y-Rita, 1972; Committee on Vision, 1986). Computer generated spatial displays are revolutionizing modern technology in automated systems such as aircraft collisionavoidance systems and virtual reality (VR) systems in which human operators interact with a computer generated image. Ironically, the net effect of automatization has been to increase the need for training human operators who have inherited critical roles that are difficult to learn and constantly changing (Rasmussen and Rouse, 1981). In fact, many automated systems operators must learn high-performance skills, which are defined by three characteristics: (a) more than 100 h are required to reach proficiency, (b) more than 20 per cent of highly motivated trainees fail to reach proficiency, and (c) substantial qualitative differences in performance exist between a novice and an expert (Schneider, 1985).
