Applying the Analytical Hierarchy Process to the development of a subjective workload rating scale

In order to evaluate the mental workload of the operators more systematically, a subjective workload rating scale named ICO (short for Input, Cognition and Output) was developed. The structure of the ICO was based on the multiple resource theory. And the Analytic Hierarchy Process was applied in the development of the ICO. 12 subjects participated in a series of experiments, and rated the ICO and the NASA Task Load Index (TLX) on the completion of each experiment. By analyzing the ICO scores and TLX scores statistically, the sensitivity, diagnostic ability, and validity of the ICO rating scale were evaluated. Results show that the ICO demonstrates satisfying sensitivity, diagnostic ability and validity, and can be applied in the design and optimization of the human-in-the-loop system.