overwhelming task loads in information processing tasks (such as command and control) is to exclude some portion of the signal flow or postpone the processing response until the peak period has passed (Hancock and Chignell, 1987, 1988). The programmer intent on representing such behavior in an engagement simulation must address the question of the information flow rate threshold for such adaptive responses. It should be noted that this question in turn raises complex measurement issues concerning the level at which task elements are defined and their relationships specified.

Some responses to cognitive overload are dysfunctional. For example, sequence sense is often lost (Hancock et al., 1994). That is, some events are sequentially related, such as the cues a tank battalion commander will receive regarding unit losses. When confronted with a high signal flow load, the commander may forget the initial signals and not keep an accurate tally of losses, thus being unaware when a threshold for withdrawal has been reached.

The relating of actions to consequences can also be faulty, particularly if there is a time delay between action initiation and outcome or between outcome and feedback (Hancock et al., 1994). Such decoupling may seem intentional when a decision maker does not perceive negative outcomes; that is, he or she adopts a form of denial.


Internal moderators of human behavior include variables such as intelligence, level and type of expertise, personality traits, emotions/affective factors, attitudes/expectations, and cultural values. These moderators are complex, they interact, and they can influence performance in multiple directions. For example, individuals with a low level of expertise and aggressive personality characteristics will probably select different strategies than individuals with a high level of expertise and nonaggressive personalities. However, the form of this relationship cannot currently be predicted. With regard to emotions, fear may result in a tendency to interpret a situation as dangerous, while anger may result in an interpretation that others are hostile. Furthermore, an individual with an aggressive personality who is fearful may behave differently than an aggressive individual who is self-confident.


The Department of Defense conducted an extensive research project on linking selection criteria to job performance (Wigdor and Green, 1991). This project, known as the Job Performance Measurement Project, involved researchers from


There is an extensive literature on cognitive workload, including major works by Wickens (see, for example, Hart and Wickens, 1990; Huey and Wickens, 1993; Wickens et al., 1997).

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