The present experiment tested the merits of nine common workload assessment techniques with relatively short periods of workload in car driving. To that end, twelve participants drove an instrumented car and performed either a visually or a mentally loading task for 10 s, 30 s, and 60 s. The results show that the 10 s peaks in visual and in mental workload are indicated well by secondary task performance and by a subjective rating list. Besides, the present version of the secondary task and, at longer loading task expositions, steering intervals appear mainly sensitive to visual workload whereas Skin Conductance Response is sensitive to mental workload only. The results lead to preliminary guidelines which will help applied researchers determining which techniques are best suited for assessing workload.
Abstract