This thesis focuses on the conceptualization and subsequent measurement of group openness and cohesion as dimensions of a group personality structure. This conceptualization and measurement were done as part of a larger research project, in which a training program for nurses was to be developed and evaluated. Earlier research had shown a relevance of personality at the individual level and team characteristics for successful transfer of training contents into daily work life following interventions such as the to be evaluated training program. However, no studies exist than examine which of these factors is the more important predictor of training transfer. In order to facilitate such a comparison, the group personality structure with the dimensions group openness and cohesion was conceptualized to parallel individual personality characteristics. The latter have been shown to be applicable to a wide range of individuals as well as being stable over time, forming a person’s personality based on overarching, latent traits. In contrast, existing concepts of group characteristics are mostly applicable to one specific type of group and their stability over time has hardly been examined. The group personality structure presented in this thesis was conceptualized to be applicable to a wide range of groups and stable over time, filling this conceptual gap. Therefore, the newly created concept enabled a more valid comparison between individual personality characteristics and group (personality) characteristics in their ability to predict training transfer for the presented study and might additionally enable comparisons between different groups in future research.
The group openness and cohesion dimensions were derived from two research branches concerned with different conceptual approaches to group characteristics: A direct approach, in which the group members rate characteristics of their group and in which those ratings are averaged to create a group score, and an indirect approach, in which the group members rate characteristics of themselves, which are then averaged to create a group score. From multiple studies involving these approaches, the dimensions group openness and cohesion were derived as group personality characteristic that represent the group’s outward and inward orientation, respectively. A new questionnaire instrument was created to measure these group characteristics. The empirical results of this thesis are presented in three research papers, in which the following conclusions are made. Group openness and cohesion are shown to be distinguishable and reliably and validly measurable constructs, stable across time and (theoretically) applicable to a large variety of groups. A detailed analysis of the individual response patterns of the team members revealed that the ratings of group openness and cohesion are influenced by the individual perspective more than by the presumed latent group characteristic and that this individual perspective is, in turn, influenced by individual personality. The indirect approach to group characteristics is found to not correlate with the newly created concept. Finally, training transfer is found to be influenced by group cohesion and group mean conscientiousness (a variable from the indirect approach), and to not be influenced by individual personality. Overall, the results point towards a larger importance of team characteristics for training transfer and for a valid conceptualization of group openness and cohesion as dimensions of group personality. The general discussion summarizes the theoretical and practical contributions of the new concepts and the results presented here, and lists limitations and future research directions. Examples for the latter include further comparisons with different operationalizations of the indirect approach to group characteristics, as well as the conceptualization of a new set of measurements that focus more on the applicability to different types of groups.