Comparing subject strategies at a process control task

Operators develop habitual responses for controlling complex systems which may be neither apparent nor verbalized. Identifying consistent patterns in their behavior can reveal these implicit strategies. Logs from a simulated process plant were used to identify production rules characterizing operators' behavior. Similarity among strategies was determined by finding the intersections and unions among the preconditions of these rules. Clusters of subjects using similar strategies were identified and compared on performance measures. This characterization of strategies provided a good account of differences in performance which were readily interpretable in terms of the task. The approach appears promising as a technique for diagnosing performance in simulator training.<>