Situation awareness (SA) has received a great deal of attention in recent years because of its well-documented role in aviation and other complex environments. In a review of more than 200 aviation mishaps, Hartel, Smith, and Prince found that a lack of SA was the leading causal factor. Likewise, Endsley asserted that SA was the single most important factor in aviation mission performance.

Although situation awareness has been identified as critical, it is not well understood. Sarter and Woods, in referring to SA of individuals, noted that "situational awareness has thus become a ubiquitous phrase. Its use is most often based on intuitive understanding; a commonly accepted definition is still missing." This lack of an accepted definition and clear knowledge about the concept is also a problem for team performance, in which SA is hypothesized to have a significant impact. There are, however, some similarities across explanations that are sufficient to provide a common base that can help in understanding the concept and provide coherence for future research. 

The purpose of this paper is to examine processes and behaviors that have been associated with team SA. This line of inquiry is important because SA plays a critical role in aviation teams and in military team decision-making environments. We postulate that this construct applies to other types of teams as well (e.g., medical emergency teams, firefighters).

In this article, we examine situation awareness on two levels. First, we briefly summarize some elements that are common to several of the proposed explanations of individual SA in order to provide a base for examining team SA. Second, we identify critical variables that are associated with team SA and describe processes and behaviors that have been proposed as contributors to its establishment and maintenance. Finally, on the basis of the information reviewed, we identify issues related to the measurement and training of team SA. These issues and the questions they raise should help to guide future research.