Selection of a Workload Metric for Evaluation of Telemedicine Applications: Literature Review and Methodological Development

A measure of cognitive workload was needed to conduct human factors evaluations of telemedicine applications. A literature review was conducted to find available metrics and select candidates for testing. Three candidate measures (the Subjective Workload Assessment Technique SWAT, NASA-Task Load Index TLXj along with its subscales, and the Modified Copper-Harper MCM) were selected using the following criteria: reliability, validity, lack of contamination, availability, sensitivity, lack of intrusiveness, diagnosticity, and cost. All metrics in the literature review, as well as the application of the selection criteria, are described in this report. Methodological development and research were then completed to develop a research paradigm for selecting the best workload metric from the three candidates. This effort included the development and norming of difficulty levels of a surrogate task in a controlled experimental protocol, the selection of a spatial abilities test, acquisition and testing of required telecommunication and recording equipment, and the iterative development and testing of a research protocol. These processes and their results are described in detail in this report.