Evaluation of control strategies in a complex space-vehicle control task: Effects of training type

The fundamental differences in operator control strategies in a complex task were evaluated in two training scenarios: in-the-loop training and out-of-the-loop training. Verbal protocols and performance measures revealed four types of complex control mechanisms dependent upon these two training approaches. The four types were display based control, open loop input control, closed loop input control, and an input-display control mix. Performance differences favored in-the-loop training, and led to the development of an open loop input control strategy. The overall results indicate that performance improvements may be achieved with operator training on the system dynamics and optimization aspects rather than operator training directed only at the optimization aspects. A "sitting by Nellie" approach such as watching an expert or watching an algorithm perform a task may be disastrous if the system dynamics are poorly understood. This study also suggests how operator strategies can be effectively used to design user-friendly aids which improve operator performance in complex control tasks.