able to get the information they need. In a team, each member has a subgoal pertinent to his/her specific role that feeds into the overall team goal. Associated with each member's subgoal are a set of SA elements about which he/she is concerned. As the members of a team are essentially interdependent in meeting the overall team goal, some overlap between each member's subgoal and their SA requirements will be present. It is this subset of information that constitutes much of team coordination. That coordination may occur as a verbal exchange, a duplication of displayed information, or by some other means. Shared SA Shared situation awareness can be defined as "the degree to which team members possess the same SA on shared SA requirements". As implied by this definition, there are information requirements that are relevant to multiple team members. A major part of teamwork involves the area where these SA requirements overlap—the shared SA requirements that exist as a function of the essential interdependency of the team members. In a poorly functioning team, two or more members may have different assessments on these shared SA requirements and thus behave in an uncoordinated or even counter-productive fashion. Yet in a smoothly functioning team, each team member shares a common understanding of what is happening on those SA elements that are common—shared SA. Thus, shared SA refers to degree to which people have a common understanding on information that is in the overlap of the SA requirements of the team members. Not all information needs to be shared. Clearly, each team member is aware of much that is not pertinent to the others on the team. Sharing every detail of each person's job would creates information overload to sort through to get needed information. It is only that information which is relevant to the SA requirements of each team member that needs to be shared. Team SA model The situation awareness of the team as a whole, therefore, is dependent upon both a high level of SA among individual team members for the aspects of the situation necessary for their job; and a high level of shared SA between team members, providing an accurate common operating picture of those aspects of the situation common to the needs of each member. Endsley and Jones describe a model of team situation awareness as a means of conceptualizing how teams develop high levels of