This digest describes and defines the various components of an expert system, e.g., a computerized tool designed to enhance the quality and availability of knowledge required by decision makers. It is noted that expert systems differ from conventional applications software in the following areas: (1) the existence of the expert systems shell, or…

This digest highlights several psychological dimensions of user-computer interfaces. First, the psychological theory behind interface design and the field of human-computer interaction (HCI) are discussed. Two psychological models, the information processing model of cognition and the mental model--both of which contribute to interface design--are…