In larger events, several organisations are involved in emergency management processes so that the co-ordination of decision making is a challenge. Team members have different characteristics such as cultural background, environment, educational background, experiences and goals, depending on their roles, and it can be difficult to draw together individual expertise to handle a problem. Therefore, understanding the situation correctly and in a shared, common way is difficult. In addition, in an emergency, information is frequently evolving, uncertain and incomplete so that information co-ordination5 requires information to be current and available in a directly
usable form for accurate team decisions.
Due to the major requirement of team work in current disaster management organisations, the concepts of shared and team situation awareness (SSA & TSA) are currently receiving enormous attention from both human factors community and disaster management (Fiore et al., 2003).
2.5.1 Shared Situation Awareness (SSA)
Shared Situation Awareness (SSA) refers to the extent of common SA requirements of team members (Endsley & Jones, 2001). Each team member has specific SA requirements for their task, some of which are common with their team member’s requirements, and these researchers define SA as, “the degree to which team members have the same SA or shared SA requirements” (Endsley & Jones, 2001).
Moreover, Endsley and Robertson (2000) suggest that successful team performance requires that individual team members have a good SA of their own elements and the same SA for those elements that are shared. Thus, SSA refers to the overlap between the SA requirements of the individual team members. This concept is illustrated in the Venn diagram of Figure 3 where the circles represent each team member’s SA requirements, and the overlapping segments depict the SSA (Endsley & Jones, 2001). The white areas of the circles indicate the information that does not need to be shared.
52 Sharing information that is not relevant to the SA requirements of other team members’ roles would only create "noise" and wasteful effort to acquire it.
Figure 2.5 Shared Situation Awareness (Endsley & Jones, 2001) 2.5.2 Team Situation Awareness (TSA)
A team is defined as “two or more people dealing with multiple information resources, who work to accomplish some shared goal” (Salas et al., 1995). Team Situation Awareness (TSA) is more complex than individual SA. Salas et al. argued that there is a lot more to TSA than just combining team members’ SA. Moreover, due to the many other cognitive, social and team factors, research into the construct is challenging, scarce and difficult and there is no consensus on exactly how TSA works.
Taking an operational view, the most widely used model of SA due to Endsley and Jones (2001) leads to a definition of TSA as “the degree to which every team member possesses the situation awareness required for his or her responsibilities” (Endsley, 1995a). Endsley argues that the success or failure of a team depends on the success or failure of each of its team members. At its simplest level, therefore, each team member has a sub goal related to his/her role that feeds into the overall team goal. A set of SA information elements is linked with each member's sub goal and these are shared with other members of the team. The shared subset of information is the basis of team co- ordination which may occur directly or be mediated by technology (Endsley & Jones, 2001). TSA can therefore be represented as a Venn diagram (Figure 2.6) in which the circles represent team members’ information relevant to their roles and the overlapping areas represent their shared information. A two-circle overlap denotes shared situation awareness (SSA) and the three-circle overlap signifies team situation awareness (TSA).
53 Teams with more than three members would clearly require diagrams with additional circles and multiple overlaps.
Figure 2.6 TSA: the goals and SA requirements of all team members (Endsley & Jones, 2001).
Endsley & Jones (2001) have extended their operational view in a model that describes the factors that help to build SSA and hence TSA (Figure 2.7). These factors – requirements, devices, mechanisms, and processes – facilitate interaction between the participants and the sharing of information so that teams can develop high levels of SSA and TSA.
Figure 2.7 Factors that build high levels of SSA and TSA (Endsley & Jones, 2001) Taking a different perspective, Salas et al. (1995) have argued that there is a lot more to TSA than just combining team members’ SA. Apparently, TSA is multi-faceted,
Team SA Requirements Information needs
Team task status
Team SA Devices Direct communication Shared displays Team SA Processes Sharing SA information Check conflicting information f k Team SA Mechanisms Shared mental models
54 comprising an individual team member’s SA, shared SA between team members and the combined SA requirements of the whole team. In this framework, TSA is mostly understood as a shared understanding of the same situation (Nofi, 2000) whereas, according to Perla et al. (2000), when we all understand a given situation in the same way it is SSA.
Salas et al. (1995) suggest that TSA comprises two important, but badly understood processes, individual SA and team processes, and depends on communication at various levels of SA. For example, perception of elements at level one SA is effected by communication of mission objectives, individual tasks and roles, team capability and team performance factors. Similarly, comprehension at SA level two is impacted by the interpretations made by other team members, so it is evident that sharing an individual’s SA leads to the development or modification of another’s SA. In addition, the mental schema limitations of an individual can be offset by information exchange and communications (Salas et al., 1995).
Salas et al. (1995) consequently defined TSA as “the shared understanding of a situation among team members at one point in time”, and concluded that “team SA occurs as a consequence of the interaction of an individual’s pre-existing relevant knowledge and expectations, the information available from the environment and cognitive processing skills that include attention allocation, perception, data extraction, comprehension and projection”.
Another approach due to Wellens (1993) uses a model of distributed decision making to describe SA during collaborative activity and suggests that the key to TSA lies in the arrangement of teams to provide adequate separation for individual SA acquisition with sufficient overlap for co-ordination. Wellens (1989) defines TSA as the “sharing of a viewpoint between two or more individuals regarding current events in the environment, their implications and projected future”.
The TSA definition used in defining this framework is provided by Shu and Fruta (2005), which is:
“Two or more individuals share the common environment, up to the moment understanding of situation of the environment, and other person’s interaction with the cooperative task.”
55 According to Shu and Furuta (2005), TSA includes two basic elements, an individual’s SA and mutual awareness. Mutual awareness refers to the awareness that individuals of a co-operative entity have of each other’s activities, beliefs and intentions. For example, if two team members A and B want to understand and act on a situation co-operatively, each of them needs to recognise the parts of the situation that he/she is responsible for, and to believe that the other member recognises their own parts of the situation and is willing to co-operate. In addition, each member must contribute a belief about the other team member’s understanding. Hence, this definition covers both the individual and shared understanding of the situation and the execution of co-operative tasks. In short, for the team of two members A and B, A’s TSA consists of three basic components (1) A’s own SA, (2) A’s belief about B’s SA and (3) A’s belief of B’s belief about his/her own (A’s) SA. If any of these is missing, the TSA is incomplete.
The complexity of interaction clearly increases with increasing team size and much work needs to be done to refine definitions and terminology, unravel interactions, and synthesise a complete picture of TSA. Only then, for example, will it be possible to answer questions such as “how much sharing of information (extent of overlap of circles, e.g. in Figures 2.5 and 2.6) is needed to ensure successful completion of a collaborative task in a given situation?”