Techniques of Subjective Assessment: A Comparison of the SWAT and Modified Cooper-Harper Scales

Abstract

This study examined two subjective mental workload assessment scales, the Subjective Workload Assessment Technique (SWAT) and the Modified Cooper-Harper (MCH) Scale. The purpose of this study was to make a direct comparison of the two scales in order to determine if both scales were equally sensitive to changes in task difficulty hence, workload. Forty introductory psychology non-aviator students were trained on an aviation like psychomotor dual-task experiment. Task difficulty was manipulated by presenting the subjects with three (low, moderate, high) levels of wind gust disturbance (turbulence) and requiring them to maintain an assigned altitude and airspeed, while responding to a visual choice reaction time secondary task. The data was analyzed using multivariate statistics. The results of the analysis found that both the SWAT and MCH were sensitive to changes in task difficulty. However, the MCH appeared to be less sensitive than the SWAT.