The effects of group decision support systems and task structures on group decision processes and outcomes : an experimental investigation
Creators: name: Lam, Simon Sing Kwong
Publisher: name: The Australian National University
Year: 1996
Subjects: subject: Decision support systems
subject: Group decision making
subject: Communication in small groups

description: This research examines whether structures of decision tasks moderate the effects of group decision support systems (GDSS) on patterns of group communication and decision outcomes of decision making groups. This research also examines the relationship between patterns of group communication and decision outcomes. Although prior research has shown that the effects of GDSS on group decision making are not uniformly positive, conditions under which the use of GDSS is appropriate and beneficial are not well understood. The characteristics of the group task are emerging as important variables that are believed to moderate the effects of GDSS on group decision making. Failure to explicitly study the role of group communication in group decision making is another reason why prior research on GDSS has yielded much conflicting evidence. This research seeks to show that the effects of GDSS on decision making processes and outcomes are task structure dependent and the effects of GDSS cannot be evaluated on the basis of outcomes alone; decision processes must also be evaluated in order to understand how decisions are made and why GDSS can improve group outcomes in some situations but provide negative effects in others. A controlled laboratory experiment was conducted with a 2x3 factorial between-subjects design, manipulating two independent variables: levels of support (GDSS support and no support) and task structures (additive, disjunctive and conjunctive). Practising managers were chosen as subjects. Using a personnel recruitment exercise as the experimental task, the structure of the task was manipulated by varying the group members’ role and information distribution. Subjects were either provided with GDSS or with no support. The experiment was administered to the subjects who were participating in a management training course. The discussion records of the decision making process were coded using a coding scheme. Other dependent variables were decision quality, decision time and perceived satisfaction with process and outcome. The research results support the hypothesis that structures of a decision task moderate the effects of GDSS on both the patterns of group communication and decision outcomes of a decision making group. GDSS significantly improve decision quality in disjunctive and conjunctive tasks. GDSS also significantly alter patterns of group communication in disjunctive and conjunctive tasks. However, no significant differences in decision quality and patterns of group communication exist between groups using GDSS and face-to-face groups in additive tasks. The results also show strong relationships between patterns of group communication and decision outcomes. The research provides strong support for the theory that an understanding of how GDSS shape the patterns of group communication is likely to provide an explanation as to why GDSS can improve group outcomes in some situations but fail to perform in others.