The Range and Consistency of Individual Differences in Continuous Work

Abstract

Two five-man teams were trained to asymptotic levels of synthetic-work performance on a multiple-task performance battery (MTPB) which required subjects to time share five individual-performance tasks and one group-performance task. Each team was then exposed four times to continuous-work and sleep-loss stresses in a repeated-measures design. Performance levels were measured in terms of 13 individual-task measures and a general mean-percentage-of-baseline measure. Individual performance decrements were found to range from 0 to 40% below prestress levels. The findings also indicated that subjects responded consistently across the four exposures to continuous work and sleep loss. Furthermore, the subjects experienced a general performance decrement across all tasks rather than a task-specific one. These findings are discussed in terms of their important implications for the design of man-machine systems and the selection of operators who are most resistant to sleep-loss stress.