TECHNIQUES OF SUBJECTIVE WORKLOAD ASSESSMENT - A COMPARISON OF SWAT AND THE NASA BIPOLAR METHODS

Two popular methods were compared: (1) the Subjective Workload Assessment Technique (SWAT) that employed a conjoint measurement procedure to confer interval scale properties on the workload ratings,l and (2) a technique under development at NASA that used an individually weighted workload score. Both methods were applied in a laboratory experiment that required the rating of a number of single- and dual-tracking and spatial transformation tasks. Both subjective assessment techniques displayed similar sensitivity to the different task manipulations. A notable difference between the two techniques was that the NASA-Bipolar ratings consistently had a smaller between-subject variability than the SWAT ratings.