distributed interactive battlefield simulations will see the performance of individual soldiers and higher-level units in terms of the individual and unit behavior they exhibit, the execution of plans they formulate, and the battle outcomes that result. Although explanations of how the behavior comes about may be useful for after-action reviews, they are not needed during simulation execution. Only the outcomes need to meet the expectations of the audiences that will observe them. Similarly, detailed rationales for how groups accomplish tasks are generally irrelevant. What is important is that the group behavior mirror that which is expected in the real world.
When viewed from the perspective of the simulation user (exclusive of developers), the characteristics of behavior that the visible and interpretable to the users of a simulation depend on the level of aggregation at which the behavior is presented. We consider first the individual players, either dismounted or associated with a vehicle. These individuals may be the individual combatants, ground vehicle or air system commanders, squad or platoon leaders, or commanders at a higher level. They may observe units at different levels of aggregation as well.
The most obvious behavior to be observed is the physical movement in the battlespace. It must be at an appropriate speed, and the path followed must make sense in light of the current situation and mission.
The detection and identification of enemy or friendly individual units in the human behavior representation must appear reasonable to the observer (see also Chapter 7). The visual search should depend on situation awareness; prior knowledge of the participant; current task demands; and external environmental factors, such as field of view, distance, weather, visibility, time of day, and display mode (unaided vision versus night vision goggles).
Decision making outcomes should reflect situation awareness and real environmental conditions (see also Chapter 6). The decisions concern such observations as which way to move given the plan and the situation presented by the opposing forces; they also concern whether to shoot, seek cover (evade in the case of aircraft or ship), or retreat. Movement decisions should be consistent and coordinated with the behavior of others in the same unit. Decisions should be consistent with the currently active goals. Ideally, individuals will exhibit behavior that reflects rational analysis and evaluation of alternative courses of action, including evaluation of alternative enemy actions, given the context. In practice, in time-critical, high-stakes situations, individual decisions are more likely to be ''recognition-primed," that is, made on the basis of previously successful actions in similar situations. For example, Klein et al. (1986) show how experienced fire team commanders used their expertise to characterize a situation and generate a "workable" course of action without explicitly generating multiple options for comparative evaluation and selection. In more recent work, Kaempf et al. (1996) describe how naval air defense officers spent most of their time deciding on the nature of the situation; when decisions had to be made about course-of-action plans, fewer than 1 in 20 decisions focused on option evaluation.