In their recent review, Wierwille and Eggemeier (1993) briefly discussed context sensitivity as a potential problem for subjective mental workload measures, a problem that we believe has not been sufficiently recognized.
If this range is restricted to the lower or upper end, a subjective mental workload scale's external validity may be compromised, especially for assessments of whether mental workload level exceeds a critical level in a system test and evaluation (Wierwille & Eggemeier, 1993).
The present experiments had two purposes: first, to determine whether range of task difficulty influences ratings on standardized multidimensional subjective mental workload measures, and second, to determine whether testing procedures might be modified to reduce context effects, if present.
These are two of the most widely used standardized multidimensional subjective mental workload techniques (Hill et al.
Given that context influenced subjective mental workload ratings, it would be desirable to develop techniques for controlling its effects.