Establishing Workload Manipulations Utilizing a Simulated Environment

Research seeking to improve the measurement of workload requires the use of established task load manipulations to impose varying levels of demand on human operators. The present study sought to establish task load manipulations for research utilizing realistically complex task environments that elicit distinct levels of workload (i.e. low, medium, and high). A repeated measures design was used to test the effects of various demand manipulations on performance and subjective workload ratings using the NASA-Task Load Index (TLX) and Instantaneous Self-Assessment technique (ISA). This experiment successfully identified task demand manipulations that can be used to investigate operator workload within realistically complex environments. Results revealed that the event rate manipulations had the most consistent impact on performance and subjective workload ratings in both tasks, with each eliciting distinct levels of workload.