Suchergebnisse

Three computer-based techniques for analyzing and simulating serial-action tasks are described. The first, called BETS, measured the efficiency, in terms of expected information, of tests made by technicians who were troubleshooting malfunctioning electronic circuits. It computed efficiency ratios for a technician's test sequences in comparison to optimal sequences. The second method, ARMAN, generated detailed time-and-motion analyses from gross descriptions of serial-action tasks and man-machine interfaces and computed the time costs of these tasks. The third technique incorporates a general model of the action-goal structure of serial-action work. It operates on this structure with special functions composed in a symbol manipulation language. This program, called TASKSYM, can generate all alternative correct ways to accomplish serial-action work and can track a subject through the performance of this work. The model includes an anti-goal structure which identifies action sequences leading to catastrophic error, e.g., electrical damage to the equipment or shock hazard to the performer. An extension of the program to computer-aided instruction is described.

Thirty-nine Navy technician trainees filled out a symptom-malfunction matrix on a blocking oscillator circuit. The technicians then attempted to solve six troubleshooting problems in the same oscillator circuit. The particular sequence of checks used by each man on each problem was combined with his symptom-malfunction matrix, via a Bayesian algorithm, to yield computer estimates of failure likelihoods for each component. The computer program predicted actual parts-replacement behaviors in about half of the cases. Those technicians who start out with valid symptom-malfunction matrices are more likely to resemble the Bayesian processor.