Attention and Mental Workload

Mental workload is still a useful concept in human factors because of its links to theories and models of attention. A good theory is the best practical tool. Mental workload is defined as an intervening variable similar to attention. It must be inferred from changes in performance. Performance declines when mental workload is too high or too low. Results from simple laboratory situations cannot necessarily be generalized directly to practical situations which tend to be more complex. Instead, laboratory experiments are used to refine models and theories that can be applied to solve practical problems. Computational models of attention and workload offer the greatest promise for practitioners. Examples of research on driver workload illustrate the dangers of applying secondary-task methodology without adequate consideration of theoretical issues.