A schema-based model of situation awareness: Implications for measuring situation awareness

Measures of pilot situation awareness (SA) are needed in order to know whether new concepts in display design help pilots keep track of rapidly changing tactical situations. In order to measure SA, a theory of situation assessment is needed. Such a theory is summarized, encompassing both a definition of SA and a model of situation assessment. SA is defined as the pilot's knowledge about a zone of interest at a given level of abstraction. Pilots develop this knowledge by sampling data from the environment and matching the sampled data to knowledge structures stored in long-term memory. Matched knowledge structures then provide the pilot's assessment of the situation and serve to guide his attention. A number of cognitive biases that result from the knowledge matching process are discussed, as are implications for partial report measures of situation awareness.