Evaluation of Work Schedules Using Psychophysiological Measures
Authors: Henning Robert A. , Wilson Glenn F. 
Published: January 2012

While the primary goal of this symposium is to demonstrate the utility of psychophysiological measures in the evaluation of work schedules, the more general goal is to promote the use of psychophysiological measures in organizational design and management research.

There are several good reasons to include psychophysiological measures in ergonomic evaluations. Foremost among these is that the information provided about worker well-being and performance capabilities cannot be obtained in other ways. Psychophysiological measures provide continuous, non-invasive, and objective measurement of an individual's response to work activities. Because of known relationships between physiological mechanisms and behavior, work-induced changes in physiological response can be used to monitor the effects of organizational design on work demand or recovery. Most would agree, however, that psychophysiological measures are seldom meaningful unless they are collected and analyzed in conjunction with other measures. In particular, psychophysiological measures can provide crucial information about worker well-being when subjective reports of distress or discomfort are biased by psychosocial factors, and also when workers compensate for increases or decreases in work demand by drawing on reserve capacity. In cases where performance measures or subjective reports are more reliable, measurement of psychophysiological responses can provide convergent results that add to the scientific validity of the research investigation. This explains why all researchers in this symposium use a balanced approach and analyze performance and/or subjective ratings in combination with psychophysiological measures.

Beyond the scientific rationale for including psychophysiological measures in ergonomics research, many of the practical difficulties researchers faced in the past have been eliminated by recent technological advances. Modern heart rate monitoring systems, for example, have noise suppression features that improve signal quality and allow data collection in real work settings. Portable data loggers enable researchers to monitor multiple physiological response measures over 24-hour periods. Handling large data sets is no longer a problem because the digital storage capability of small computers is nearly unbounded. Data analysis software, such as time series analysis, has become more sophisticated and easier to use. What all this means in practical terms is that it is no longer necessary to dedicate a major portion of one's career to surmount the technical problems associated with psychophysiological research.

The wide range of work scheduling topics covered in this symposium is a good example of the utility of psychophysiological measures in ergonomics research. Specific work scheduling topics include: appropriate rest break length at different times of the work day to ensure adequate recovery from sustained cognitive demand (Boucsein and Thum), methods for verifying the health and safety of underground miners working 12-hour shifts in shortened work weeks (Duchon and Smith), the impact of self-managed rest breaks on well-being during continuous computer work (Henning, Callaghan, Guttman, and Braun), and how assessing work efficiency during a cognitive task can be used to evaluate the effectiveness of work/rest schedules (Meijman). While the specific goals of these studies may differ, in each case the use of psychophysiological measures enhances the scientific validity of the research and provides important information about the relationship between work schedule design and worker well-being.