Group development as a mediator of the effects of leadership style on team effectiveness in certain and uncertain team tasks

Abstract

[eng] 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.

[spa] El objetivo principal de este proyecto fue investigar, por una parte, los mecanismos que unen dos procesos psicosociales importantes, el liderazgo transformacional y el desarrollo del grupo, y la efectividad del grupo en tareas inciertas y escasamente inciertas. El objetivo del estudio fue analizar las características psicométricas del questionario Group Development (GD). En una organización de investigación alemana, recolectamos datos de 501 miembros y 104 líderes de equipos. Los participantes contestaron el cuestionario GD y otros ítems relacionados con procesos grupales. Se confirmó la estructura unidimensional del GD y encontramos una buena consistencia interna y evidencia de validez del instrumento. El segundo estudio se orientó a evaluar, en una muestra alemana, la calidad psicométrica del MITAG (Modelo de Incertidumbre de las Tareas del Grupo). Los sujetos respondieron al MITAG, junto al Job Diagnostic Survey (JDS) y el instrumento alemán "Facetas ambiguas en el trabajo" (Ambiguitätsfacetten der Arbeit”- AfA). No se reprodujeron los 4 factores originales del MITAG. Identificamos 3 nuevos factores: "falta de claridad de objetivos", "nuevas situaciones", y "falta de rutina". La nueva estructura demostró buena consistencia interna y evidencia de validez. El objetivo del tercer estudio era poner a prueba un modelo tipo entrada-mediador-salida de las interrelaciones entre el liderazgo transformacional, el desarollo del grupo, la incertidumbre de tarea, la interdependencia de tareas y la efectividad grupal. En una muestra de 107 equipos (408 individuos) de una organización de investigación y desarollo (I&D) pusimos a prueba el modelo propuesto aplicando modelos de ecuaciones estructurales (MES). Los resultados indicaron que dos variables median parcialmente el efecto del liderazgo transformacional sobre la efectividad (p < .05): el desarrollo del grupo, y también “nuevas situaciones”, un caracteristica de tarea que se refiere a demandas inestables que llegan de fuera del equipo. Aunque los líderes transformacionales definieron mejor los objetivos (p < .05), esto no contribuyó a la efectividad del grupo. Las relaciones identificadas fueron robustas con respeto a posibles sesgos de fuente común. Las limitaciones del estudio son fundamentalmente la inclusión de datos solo transversales y una variación menor de lo esperado en la incertidumbre de tarea entre las diferentes ocupaciones.