SUPERVISORY CONTROL IN A DYNAMIC AND UNCERTAIN ENVIRONMENT - A PROCESS MODEL OF SKILLED HUMAN ENVIRONMENT INTERACTION

An understanding of how both psychological and environmental factors m utually constrain skilled behavior is required to effectively support human activity. As a step toward meeting this need, a process model of skilled human interaction with a dynamic and uncertain environment is presented. The model was able to mimic human behavior in a laboratory task requiring one- and two-person crews to direct the activities of a fleet of agents to locate and process valued objects in a simulated world. Reflective of the need to explicitly consider both environmenta l and cognitive influences on behavior, the process model is a pair of highly interactive components that together mimic the behavior of the human-environment system. One component is a representation of the ex ternal environment as a dynamically changing set of opportunities for action. This environmental component is based on the ecological viewpo int that relations indicating the match between the human's capacity f or action, and actions made available by the environmental structure, should serve as primitives in the description of the environment for t he skilled performer. The second component is a dynamic representation of skilled human decisionmaking and planning behavior within the envi ronment so described. Modeling both human and environment in an integr ated fashion allowed for a description of behavior as being mutually i nfluenced by the external environmental structure and an internal prio rity structure over available actions. Sensitivity to environmental st ructure ensured that action selection opportunistically exploited the dynamic possibilities for action afforded by the external situation, w hereas the priority structure ensured that action selection was also c onsistent with task goals. The process model is an expression of a gen eral theory of skilled interaction assuming that perception and action mechanisms sensitive to environmental constraints are responsible for generating much of behavior, and where the need for additional cognit ive processing of internal representations (e.g., problem-space search , multiple option comparison) may result from environmental designs th at do not adequately support the perceptual guidance of activity.