Goodness-of-Fit in the User-Computer Interface: A Hierarchical Control Framework Related to "Friendliness"

A hierarchical model is used as a vehicle to integrate concepts related to user-system interfaces from a variety of different disciplines. The model is based on the notion that the user and the system constitute two independent control systems and that proper intersystem communication can take place only when each operates with appropriate expectations about the control strategies used by the other. Obstacles to efficient communications on each level of the hierarchical model are identified, and implications for effective interaction strategies are discussed.