Cognitive correlates of ultrasonic inspection performance

This study provided a detailed examination of the thought processes required for conducting successful ultrasonic inspections of nuclear power plant components. When employed to detect or estimate the size of defects in components such as pipes and nozzles, an ultrasonic inspection can be a demanding cognitive task. A successful result requires the mental manipulation of a substantial amount of relevant information: knowledge about the component inspected, understanding of available ultrasonic techniques, and interpretation of an almost infinite variety of signal-characteristics obtained during the inspection. Reaching a correct conclusion from an inspection is a function of both the validity of the information obtained and the effectiveness with which the information is interpreted and weighed. Previous efforts to improve ultrasonic inspection performance have been directed mainly to the improvement of techniques and training for obtaining information. This study addressed improvement of the cognitive processes -- the mental manipulations required to reach a correct conclusion. The study was designed to learn what inspectors were doing and thinking while applying ultrasonic inspection techniques, and to relate key cognitive elements to inspection performance -- that is, to determine what aspects of these cognitive processes discriminate between effective and ineffective inspections. To this end, tape-recorded commentarymore » was obtained and analyzed from 235 inspections of pipe-weld specimens. 26 refs., 39 figs.« less