Decision Making in the Modern Workplace: The Impact of Team and Knowledge Structure

In response to a growing competition and pressure to innovate, organizations have started to structure work around groups of multiple employees. Instead of breaking down tasks into individual pieces, larger clusters of tasks are assigned to teams of knowledge workers with different fields of expertise. This shift in work design is supposed to provide organizations with an increased access to the expertise and knowledge of their workforce (Kellermanns, Floyd, Pearson, & Spencer, 2008). Teams are assumed to integrate multiple perspectives and different skill sets into high quality decisions and innovative products (Brodbeck, Kerschreiter, Mojzisch, & Schulz-Hardt, 2007). However, research has repeatedly cast doubt on the intuitive expectation that groups benefit from a lager body of knowledge and collective processing of information. Not only do their members often succumb to cognitive biases when processing available information (e.g., Fischer, Greitemeyer, & Frey, 2008; Janis, 1982; Kray & Galinsky, 2003), they also most commonly fail to disseminate unshared information in the first place (e.g., Stasser, 1992; Stasser & Titus, 1985; for a review, see Wittenbaum & Park, 2001). In order to improve team performance, organizations typically invest in optimizing team composition. Attracting the greatest talents, selecting team members based on cultural fit, or ensuring diversity are popular examples of how companies try to influence their teams’ functioning (e.g., Bell, 2007; Moreland, 2006). Yet, in order to actually reach superior solutions, knowledge worker teams must also coordinate their distributed expertise, share information effectively, and integrate individual viewpoints into their final decisions. Thus, it is equally important to learn which structures and processes help these teams – once they are set up – to actually pool their informational resources. While researchers have started to study the impact of structural components on team performance, inconsistent findings call for a deeper understanding of the factors that determine when and why these components should be employed. The present dissertation aims to enrich our understanding of how teams should be structured internally to make high quality decisions. It focuses on fundamental group structures and members’ collective knowledge structure while taking the conditions of the modern workplace into account. Two studies provide much needed empirical data by directly comparing the decision making performance of self-organized versus hierarchically structured teams. In addition, the studies give insights into the role of meta-knowledge structures, as defined by a transactive memory system (TMS), in group decision making. This thesis includes four main chapters. A general introduction is given in Chapter 1. It illustrates the importance of group decision making in light of current economic trends and reviews the scholarly literature on team effectiveness and decision making. Two research papers, presenting the empirical studies of this dissertation, will follow in Chapter 2 and Chapter 3. Although the studies are connected, each chapter covers a standalone research paper with an introduction, a method and results section, as well as a discussion of the findings. Research Paper I (Chapter 2) examines the causal effects of group structure and TMS on decision quality under conditions of distributed knowledge. Employing the hidden profile paradigm (Stasser & Titus, 1985), a group experiment was conducted in the laboratory. Groups had to solve a decision making task that necessitated the exchange of information in order to reach the best result. Both group structure (self-organized vs. hierarchically structured) and knowledge structure (with TMS vs. without TMS) were manipulated, resulting in a two by two factorial design. A total of 267 university students participated in the experiment. The results of this experiment revealed two main effects. First, decision quality was higher in self-organized than in hierarchically structured groups. Second, groups with TMS made better decisions on average than groups without TMS. Both effects were found to be mediated by improved information sharing among group members during discussions. Specifically, group members’ bias towards already shared information was attenuated by a self-organized group structure as well as by the development of a TMS. Overall, the findings presented in Research Paper I suggest that a self-organized internal structure and a TMS are conducive to groups’ decision quality when knowledge is distributed among group members such that they have to work interdependently (i.e., they need each other to accomplish the task). It is precisely these circumstances that are becoming increasingly relevant in present-day organizations. Research Paper II tests a path model derived from the experimental findings by using field data from a large organization. This two-step approach served to increase the external validity of findings. A cross-sectional survey study was conducted at a publicly traded company in the information technology sector. Data from a total of 1129 employees largely confirmed the hypothesized model. In support of the experimental study, both the degree of self-organization and the development of a TMS were positively related to teams’ perceived decision quality. Improved knowledge sharing among team members partially explained these positive relationships. Results further showed that task interdependence is a moderator of the indirect effects of TMS and team structure on decision quality through knowledge sharing. More precisely, the mediated relationships were stronger for higher levels of task interdependence compared to lower levels of task interdependence. Together, the two studies provide strong empirical evidence for the advantage of more autonomous team structures over hierarchical ones in decision making situations that involve a high degree of interdependence. They further point to the supportive role of TMSs in exactly these situations. Additionally, this research started to explore the mechanism underlying the positive effects of self-organization and TMS. It finds knowledge sharing to be an important mediator for the success of knowledge worker teams. In the final chapter, this thesis closes with a general discussion of the two studies, including a synthesis of their findings, suggestions for future research, and an evaluation of the theoretical and practical implications. In conclusion, the present dissertation combines previous research on cognitive team processes (e.g., Lewis, 2003; Mohammed & Dumville, 2001), hierarchy (e.g., Anderson & Brown, 2010), and socio-technical systems theory (e.g., Cummings, 1978; Pasmore, Francis, Haldeman, & Shani, 1982), thus bridging separate research traditions. Its empirical findings endorse the efforts of organizations to flatten their structures and promote knowledge sharing