Extending Long Term Working Memory Theory to Dynamic Domains: The Nature of Retrieval Structures in Situation Awareness

Research suggests situation awareness supports operator performance (e.g., Durso, Truitt, Hackworth, Crutchfield, & Manning, 1998), however no consensus definition exists (Rousseau, Tremblay, & Breton, 2004). One framework that incorporates most definitions is Endsley’s (1995a) hierarchical view. It includes perception of elements in the environment, comprehension, and projection of future status. Although the literature has slowly begun to accept a hierarchical view of situation awareness, evidence supporting this claim is limited and indirect. Several researchers have suggested that long-term working memory (LTWM), a theory of a memory process that explains how individuals can rapidly encode information in long-term memory and retrieve information from long-term memory, supports the development of situation awareness. However, a critical review of past research reveals that it cannot be concluded that long-term working memory was being employed, and therefore the role that LTWM plays in situation awareness is still uncertain. To address these issues, ten instrument-rated pilots provided verbal reports while watching various flight scenarios unfold. Periodically, the simulation froze and the screen went blank. While the screen was blank, pilots answered questions about the current flight situation either immediately or after completing a 30 second working-memory-intensive task that precluded working memory involvement in performance. Responses to the questions were used to assess pilot situation awareness. Results indicate that situation awareness is hierarchical in nature and that the familiar mechanisms of LTWM are evident in pilot verbal protocols and measures of situation awareness. Hierarchical regression analyses revealed that characteristics associated with pilot training methodologies in conjunction with familiar mechanisms of LTWM predict measures of situation awareness. It was also revealed that pilots focus on position and control information more so than specific instrument values. Data are consistent with pilot utilization of a retrieval structure where the pilot’s mental representation of the situation is driven by strategy. They are also consistent with a comprehension-based model of dynamic environments (Durso, Rawson, & Girotto, 2007). Finally, these data suggest that an event-based training technique may facilitate developing and maintaining situation awareness