The Effect of a Priori Probability and Complexity on Decision Making in a Supervisory Control Task

Abstract

In the present study we investigated how monitoring and fault management in a ship control task are affected by complexity and a priori probability of disturbances. Participants were required to supervise four independent shipping subsystems and to adjust the subsystems whenever deviations occurred. However, in order to apply the correct action, they first had to diagnose the cause of the deviation by requesting further subsystem information. Complexity and a priori probability were manipulated by varying the number of disturbances occurring simultaneously and the disturbance rates over subsystems. In general, the results indicate that the participants ignored the monitoring function when they were diagnosing a disturbance. Results also show evidence for “cognitive lockup”: Despite the possibility of stabilizing additional system faults and, consequently, increasing their time for diagnosis, participants tended not to interrupt an ongoing fault-finding process. Still, large individual differences were found in both the selected strategy and reasoning abilities.