Generic Workload Ratings of a Mobile Air Defense System (LOS-F-H)

Operator workload (OWL) scales were used to obtain ratings of generic mission scenarios and tasks for a mobile air defense missile system (LOS-F-H) following a candidate-selection field evaluation. NASA TLX, SWAT, Overall Workload (OW), and the Modified Cooper-Harper (MCH) ratings were obtained from both crew and Subject Matter Experts (SMEs). Jackknife factor analysis revealed the presence of only a single “OWL” factor for both crew and SMEs (explaining 75.9% and 82.6% of the respective total variances) and indicated a significant (p < 0.00005) ordering of the mean factor loadings: TLX (0.924) was significantly greater than OW (0.905) and MCH (0.904), which were greater than SWAT (0.778). Subsequent analysis of OWL factor scores indicated that the crew and SMEs yielded essentially equivalent evaluations of OWL for the system variables investigated. This analysis also indicated that the highest levels of OWL were obtained for the track-to-intercept task during dual Rotary-Wing (RW) and Fixed-Wing (FW) attacks, although the ID/IFF task during a dual RW attack was almost as high. These findings are discussed in the context of a methodology for assessing OWL.