ity and its consequences: demands for expertise, flexibility, and adaptability. Furthermore, military teams are increasingly composed of people who differ in culture, ethnicity, gender, age, and other externally apparent individual characteristics. Consider, for example, American infantry soldiers who receive combat training in small units that are relatively homogeneous in age and language and who have been both raised and trained in the United States. Then these soldiers suddenly find themselves in teams of Iraqi police trainees, patrolling the streets of Baghdad with teammates who cannot speak their language and have little or no shared experiences, either culturally or in tactical training. The mix of technical and interpersonal skills, along with those of temperament and adaptability needed to perform in such teams is critical to soldiers’ survival as well as the success of the mission.
From a technical rather than a social perspective, teams are increasingly imbedded in technological systems in which the boundaries between human and nonhuman functions are inextricably confounded. Cockpit crews believe that they fly aircraft; designers and engineers believe that the technology flies aircraft. Both are right and both are wrong. Given the complexity of interacting systems in today’s aircraft, precisely assigning the percentage of responsibility to humans or machines is impossible.
Definitions of teams most similar to those in the military typically assume that they are composed of two or more individuals who interact socially; possess one or more common goals; perform tasks valued by the organization in which the team is embedded; possess some interdependencies with respect to workflow, goals, and outcomes; have roles in the team that may or may not differ in status and responsibilities; and are embedded in a larger organizational system. Similar characteristics were articulated by Salas, Dickenson, Converse, and Tannenbaum (1992) and appear in much of the research literature on work teams (e.g., Alderfer, 1977; Argote and McGrath, 1993; Hackman, 1992; Hollenbeck et al., 1995; Ilgen, 1999; Kozlowski and Bell, 2003; Kozlowski, Gully, McHugh, Salas, and Cannon-Bowers, 1996; Kozlowski, Gully, Nason, and Smith, 1999; and Kozlowski and Ilgen, 2006). This definition of teams includes important contextual conditions. Specifically, the teams exist to perform tasks, and they are rarely free-standing units but are embedded in larger organizational systems.
Implicit in the inclusion of task performance as a defining characteristic of teams is the fact that teams exist to serve some purpose and that the effectiveness of the team is important. The model that has guided research on team effectiveness for the last 30 years is the input-process-output (I-P-O) heuristic model usually attributed to McGrath (1964). Inputs are resources