Individual differences and the effects of an information aid in performance of a fault diagnosis task

Two experiments are reported that investigated the performance of operators in a fault diagnosis task. Naval engineers working in the Ship's Control Centre (SCC) on board of frigates of the Royal Netherlands Navy were asked to solve a number of unfamiliar fault problems. In the first experiment, it was shown that there was a high correlation (0.85) between the number of problems correctly solved and the availability of system knowledge. In addition there was an effect of the level of formal education. In a second experiment it was shown that the provision of a simple help facility that compensates for a lack of system knowledge leads to a substantial increase in the number of problems that were correctly solved. The percentage of correct solutions increased from 62 to 89%. This increase was the same for operators with either an electrical engineering or a mechanical engineering background although the former group performed slightly better than the latter. These results show that the conclusion of Morris and Rouse (1985a) that instruction in the theoretical principles on which a system is based is less effective than the training of diagnostic procedures, underestimates the importance of system knowl-edge for the solution of fault diagnosis problems.