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2018
Doctoral Thesis
Titel
Group development as a mediator of the effects of leadership style on team effectiveness in certain and uncertain team tasks
Abstract
The main objective of this research project was to investigate the mechanisms linking two important psychosocial processes, transformational leadership and group development on the one hand, to team effectiveness in certain and uncertain team tasks on the other. The objective of the 1st study was to analyze the psychometric characteristics of the Spanish Group Development (GD) questionnaire in a German sample. In a German research organization, we collected data from 501 team members and 104 team leaders. They answered the GD questionnaire and items related to other group processes (democracy, mutual trust, team spirit, and motivation/interest in team tasks). Confirmatory Factor Analysis (CFA) confirmed the unidimensional factor structure of the Spanish original for the German GD instrument. It showed good internal consistency and evidence of validity. The GD correlated as expected to constructs measured with other established instruments. We also confirmed its measurement invariance regarding gender and job type. The 2nd study was aimed at evaluating the psychometric quality of the Spanish group tasks' uncertainty model MITAG (Spanish: Modelo de Incertidumbre de las Tareas del Grupo) in a German sample. The participants were the same as in the 1st study. They answered the MITAG, as well as selected items from the Job Diagnostic Survey (JDS) and from the German instrument Ambiguitätsfacetten der Arbeit (AfA). Confirmatory factor analysis did not reproduce the original 4- factor structure of the MITAG in the German sample, although the 3 newly identified factors, unclarity of goals, new situations, and non-routine, showed a resemblance. Additionally, results showed sound internal consistency as well as evidence supporting the validity of the new factors. However, the new structure was not gender-invariant. The objective of the 3rd study was to test an Input-Mediator-Output (IMO) model linking transformational leadership, group development, task uncertainty, task interdependence and team effectiveness. We aggregated the data provided by 408 members from a German R&D organization at team level, resulting in a sample of 107 teams. We tested the proposed model with structural equations modelling. We found that group development - as a mediating process - and the task uncertainty factor of new situations - a structural aspect that refers to unstable demands from outside the team - partially mediated the effect of transformational leadership on team effectiveness in R&D organizations (p < .05). Although transformational leaders reduced unclarity of goals (p < .05), this did not contribute additionally to team effectiveness. The identified relationships were robust when checking for common source bias. Limitations include cross-sectional data and a lower than expected variance of task uncertainty across different job types. The study contributes to understanding how knowledge worker teams deal effectively with task uncertainty and confirms the importance of group development in this context. To our knowledge, it was the first study to examine the effects of transformational leadership and team processes on team effectiveness while considering the task characteristics uncertainty and interdependence.
ThesisNote
Barcelona, Univ., Diss., 2018
Verlagsort
Barcelona