Mental workload is one of the most important constructs of interests for Human Factors researchers. Adequately assessing the amount of mental workload that people experience while performing tasks under specific conditions is essential for the design of safe and efficient systems. Due to its ease of use, the NASA TLX has become the most widely used method of measuring mental workload. However, its psychometric properties are still questionable. The purpose of this study was to examine the extent of measurement invariance of the TLX and raise awareness in the Human Factors community. Two hundred participants reported the amount of mental workload they typically experience while driving in urban and rural areas and across the country. Results indicated that the TLX lacked scalar invariance, thereby biasing the estimation of mean scores and making the examination of mean differences misleading. These findings suggest that researchers should first examine the extent of measurement invariance of the TLX before they proceed to make inferences about mean differences in the amount of mental workload reported by participants under different conditions.

Anticipatory thinking is a critical cognitive skill for successfully navigating complex, ambiguous systems in which individuals must analyze system states, anticipate outcomes, and forecast future events. For example, in military planning, intelligence analysis, business, medicine, and social services, individuals must use information to identify warnings, anticipate a spectrum of possible outcomes, and forecast likely futures in order to avoid tactical and strategic surprise. Existing methods for examining anticipatory thinking skill have relied upon task-specific behavioral measures or are resource-intensive, both of which are challenging to scale. Given the increasing importance of anticipatory thinking in many domains, developing a generic assessment of this skill and identifying the underlying cognitive mechanisms supporting it are paramount. The work reported here focuses on the development and validation of the anticipatory thinking assessment (ANTA) for measuring the divergent generative process of anticipatory thinking. Two-hundred and ten participants completed the ANTA, which required them to anticipate possible risks, opportunities, trends, or other uncertainties associated with a focal topic. Responses to the anticipatory thinking and divergent thinking tasks were rated by trained raters on a five-point scale according to the uniqueness, specificity, and remoteness of responses. Results supported the ANTA's construct validity, convergent validity, and discriminant validity. We also explored the relationship between the ANTA scores and certain psychological traits and cognitive measures (need for cognition, need for closure, and mindfulness). Our findings suggest that the ANTA is a psychometrically valid instrument that may help researchers investigate anticipatory thinking in new contexts.

The present study investigated the effects of sonification pulse rate and sensor reliability on operator trust and mental workload. Processing resources and operator trust were sensitive to both pulse rate and sensor reliability. These findings suggest that setting pulse rates to 60 pulses per min may have considerable benefits in critical task environments.

Research on human trust in automated systems has been frequently limited by the use of inappropriate and inaccurate scales of human-machine trust. An attempt is made here to validate a scale proposed by Jian, Bisantz, and Drury (2000) that measures trust and distrust in automated systems. Sixty participants completed a patient monitoring task with the aid of an imperfect signaling system. Confirmatory factor analyses were conducted using LISREL 8.0 to determine the best fitting measurement model. Chi-square difference tests indicated that the best fitting model was the 2-factor oblique model. These results suggest that when using the System Trust Scale, researchers should treat trust as a multi-dimensional construct comprising of two distinct, yet related, factors. Implications for future research and measurement development are discussed.