It's all relative: defining mental workload in the light of Annett's paper

Annett (2001) has made an in-depth critique of subjectivity in science, concentrating not only on those rating scales which are extensively used in ergonomics, but also the very philosophy of subjectivism itself. The present authors take this critique and use it to reappraise their own interpretation of mental workload, a key concept popularly assessed by subjective measurement. Having recently proposed a definition of mental workload (Young & Stanton, 2001), the present commentary considers deeper problems of subjectivity in the interpretation, perception, and measurement of mental workload. It is realised that there are fundamental problems inherent with such a subjective concept, particularly concerned with the dependence on context and lack of an absolute metric. However, it is also noted that the very point of ergonomics is to address contextual influences on human performance. Therefore, in the absence of a complete paradigm shift in ergonomics, the discipline will have to either accept or find ways of coping with the problems of subjectivit