The aim of the present thesis was to empirically investigate the four-phase team adaptation process as suggested in the theoretical model of Rosen, Bedwell, Wildman, Fritzsche, Salas, and Burke and provide a better understanding of its dynamic and complex nature. Five experimental studies were conducted in an effort to provide evidence with regards to the ways this process is in fact performed, and how it is related to team properties and team adaptive outcomes. In the first two empirical studies presented (...) in Chapter 2, the first behavioral instrument for capturing the four-phase team adaptation process as proposed by Rosen et al. was developed and validated. The four developed behaviorally anchored rating scales demonstrated excellent psychometric properties. In the subsequent empirical study presented in Chapter 3, the relationship of the overall four-phase team adaptation process with team properties and team adaptive outcomes was investigated for the first time in team adaptation research. Previous adaptation exposure and updated team cognitive structures positively influenced the team adaptation process. The first three team adaptation phases, not the overall process, predicted independently post-change team performance, and previous adaptation exposure reduced the time needed for team decision making for a novel task. In Chapter 4, two empirical studies investigated whether teams executed the team adaptation process as Rosen et al.’s model postulates. The positive relationship among the four team adaptation phases was supported, however, teams performed both theory-conform and theory-non-conform phase sequences. A theory-conform executed team adaptation process was not related to team adaptive performance but instead, theory-non-conform phase sequences and the timing of the executed phases. Overall, the research presented contributes to the field of team adaptation by presenting the first instrument for capturing the overall four-phase team adaptation process, by providing first evidence about the relationships between the team adaptation process, team properties and team adaptive outcomes, by empirically testing for the first time the theoretical team adaptation process model from Rosen et al. and by extending it based on the evidence found, and finally, by providing empirically validated guidelines and a tool that can assist practitioners to promote the team’s ability to adapt. (shrink)