Recommendations for Mental Workload Measurement in a Test and Evaluation Environment

Abstract

Research performed during the last decade on estimation of mental workload has resulted in a subset of techniques exhibiting global sensitivity. Other techniques have also been demonstrated to have sensitivity in particular applications and can be used for diagnostic purposes. This paper reviews techniques that have shown sufficient sensitivity and robustness to be used in test and evaluation. Topics such as time scale considerations, available documentation, and appropriate procedures are also discussed. Recommendations are then made for workload estimation in test and evaluation situations.

Effects of VDT and paper presentation on consumption and production of information: Psychological and physiological factors

“…The measurement of mental workload can be divided into three major categories (Wierwille & Eggemeier, 1993): (i) subjective measures, e.g. the NASA task load index [TLX] (Hart & Staveland, 1988) and The Subjective Workload Assessment Technique [SWAT] (Reid & Nygren, 1988) where respondents rate their subjective experience of a task on a series of scales; (ii) measures of physiological correlates, e.g.…”

NATO Guidelines on Human Engineering Testing and Evaluation

“…But that depends on the difficulty level of the task and the familiarity with NASA-TLX. When system safety is an important aspect, a possible solution to this problem might be to use postmission subjective ratings that were supported by videotapes of the mission (Wierwille and Eggemeier, 1993).…”

“…distinguish about 26 different classes of secondary tasks (e.g., choice reaction time tasks, tracking tasks, monitoring tasks etc.). In contrast to the external secondary tasks the embedded secondary tasks (e.g., radio communication when flying an aircraft) are part of normal system functions (Wierwille and Eggemeier, 1993). They appear as a natural and integral part of the task of interest and reduce the main problems of conventional external secondary tasks: task intrusion, poor operator acceptance, and high implementation demands .…”

“…From this the conclusion should be drawn that physiological methods should only be used in addition to subjective workload measurement methods. They can be applied when implementation demands under field conditions are low and when unobtrusive and continuous measures of workload are needed (Wierwille and Eggemeier, 1993).…”

“…When a secondary task responds very sensitive, this shows, that there is considerable overlap in the processing resources of the primary and the secondary task (Wierwille and Eggemeier, 1993). That is why secondary tasks can be used as diagnostic tools.…”