Workload and Situation Awareness
Christopher D. Wickens
University of Illinois
Workload and situation awareness are two constructs that have emerged in applied psychology over the last 25 years, and have generated a tremendous amount of research and academic pondering. They have much in common, but also some important distinctions. In the following, we discuss each concept in turn, then address their commonalties, their critical differences, and finally focus on their interrelation and interplay in complex human performance activities.
The concept of mental workload has been proposed as an inferred construct that mediates between task difficulty, operator skill, and observed performance (Moray, 1979). Thus, increasing difficulty characteristics of the task (e.g., high time pressure, high working memory demands) or characteristics of the operator (e.g., low skill level), often, but not always degrades performance. However, these variables are said to always increase the mental workload of the task and thereby affect the potential for task performance, through the mediating effect of resource demand. The more difficult task or the less skilled operator requires more resources to perform at a constant level, hence leaving fewer resources available to deal with an unexpected increase in task difficulty or the requirement to perform an added “secondary” task.
To the extent that workload can be defined in terms of the resources invested in a task (and therefore inversely related to the reserve resources), one can also speak of workload increasing, as more resources are invested into a task of constant difficulty, by an operator of constant skill level. Thus,
Questia, a part of Gale, Cengage Learning. www.questia.com
Publication information: Book title: Stress, Workload, and Fatigue. Contributors: Peter A. Hancock - Editor, Paula A. Desmond - Editor. Publisher: Lawrence Erlbaum Associates. Place of publication: Mahwah, NJ. Publication year: 2001. Page number: 443.
This material is protected by copyright and, with the exception of fair use, may not be further copied, distributed or transmitted in any form or by any means.