Workload Assessment: Progress During the Last Decade

Over the last decade, considerable research has been conducted on the construct of operator workload and its measurement. From this research, both theory and methods have evolved to provide valid assessment of this construct. Two classes of assessment methods, secondary tasks and subjective scales, dominate the literature at this time. This paper traces the development of both methods, ties their use to current theories of human processing resources, and evaluates both with respect to five criteria.