Effect of Type of Task and Number of Inspectors on Performance of an Industrial Inspection-Type Task

Abstract

Two hundred forty subjects working alone and in pairs performed three different versions of a task similar to industrial inspection: a rating task and spatial and temporal two-alternative forced-choice (2AFC) tasks. Performance was worse on the rating task than on the 2AFC tasks, and the spatial and temporal 2AFC tasks were performed equally well. These results could signify that performance is impaired more by demands made on long-term memory than by demands made on perception and sensory memory, or that asking subjects to compare items is fundamentally different from, and easier than, asking subjects to judge items in absolute terms. Individual differences in performance were marked, but performance was inconsistent across different versions of the inspection task. When subjects worked in pairs, performance was comparable to that obtained by requiring items to pass two inspections by individual subjects. However, a single inspection by subject pairs required less time than two inspections by individual subjects. The practical implications of these findings are discussed.