Assessing the Validity of SWAT as a Workload Measurement Instrument

Abstract

The Subjective Workload Asssessment Technique (SWAT) carries with it the implicit assumption that people can accurately predict the amount of mental workload they would experience under various levels of three component dimensions. Research suggests that the perceptions of these dimensions may not be independent. This study was designed to measure the subjective interactions between the dimensions used in SKAT. Mental workload was generated using a text editing task in which the dimensions were manipulated independently. Results revealed significant positive correlations between the subjective levels of the three dimensions. That is, when a subject experienced a high level of one dimension, s/he also tended to rate the other two dimensions high. It may be unreasonable to assume that people can accurately predict the magnitude of these interactions when performing the ranking process which is used to derive the workload scale.