Abstract

In order to examine the social influence of group decision rules, task certainty, and response type on group decision making process, an experiment I and II were conducted. In experiment I, a 3(decision rules: unanimity/majority/truth-wins) x 2(task certainty: certain/uncertain) x (2)(response types: public/private) factorial design was used with the last variable as a repeated measure. In experiment II, the same design was used but task certainty and response types were manipulated as within-subject variable. As predicted, interaction effects between decision rules and response types were supported both in experiment I and experiment II. Also, a three-way interaction effect was statistically significant in the experiment I. The simple effect analysis revealed that differences among three decision rules were statistically significant only in the certain task-public response condition. These results supported the hypothesis that the task certainty and response types play a important role in group decision making process in conjuntion with decision making rules. Finally, the results of this study were discussed the effects and the processes of influence in group decision making.