There are a number of ways to introduce stressor/moderator effects into situation awareness models based on expert systems, such as the following:
Content parameters—number of rules, type/content/complexity of rules
Processing parameters—speed and accuracy of matching, type of conflict resolution, speed of conflict resolution
All categories of individual differences can be represented in a situation awareness model based on expert systems. Varying levels of skill and training could be represented by varying the number and content of individual rules—these include both the triggering antecedent conditions and the consequents for identifying specific situations. The degree of certainty associated with the assessment, which is a function of both skill level and affective personality factors, could be modeled by varying the degree of matching accuracy required for rule triggering. Differences in situation assessment style could be represented by specific assessments associated with particular triggering conditions. Thus a model of an overly cautious commander could have a preponderance of situations characterized by high blue losses, while a more aggressive and risk-tolerant model could include a higher number of red loss consequents. Other style preferences, such as speed of assessment or specific requirements for certainty, could be modeled in terms of processing parameters, controlling the speed of rule matching and execution and the certainty of rule activation strength required to trigger action.
Additional discussion of how moderators can be introduced into production rule decision-making models, specifically Soar and adaptive control of thought (ACT-R), is provided in Chapter 6. That discussion is directly pertinent as well to a situation awareness model based on expert systems.
An approach similar to that used for models based on expert systems can be used to incorporate stressor/moderator effects into situation awareness models based on case-based reasoning. For example, the following parameters could be included in such a model:
Content parameters—number of cases, elaboration of cases, type and number of index features
Processing parameters—speed and accuracy of matching index cases, sophistication of adaptation rules
As with the expert system-based models, all categories of individual differences can be represented through suitable incorporation of moderator variables into episodic or case-based reasoning models (see Chapter 5 for more discussion).