The Subjective Workload Assessment Technique: A Scaling Procedure for Measuring Mental Workload

Mental workload is proposed to be a multidimensional construct that can be largely explained by three component factors: Time Load, Mental Effort Load, and Psychological Stress Load. In this paper, we describe a subjective scaling approach, the Subjective Workload Assessment Technique (SWAT), that captures this multidimensional nature of mental workload. We describe the SWAT procedure as a two-phased method that includes (a) a scale development phase based on conjoint measurement and nonmetric scaling, and (b) an event scoring phase. The development of SWAT and its measurement foundations are discussed. Recent research illustrating SWAT's widespread utility and its sensitivity as a measure of perceived mental workload is summarized.