Abstract:  According to sociological theory, in group decision making, subgroups and interaction among the subgroups widely exist. Members from different subgroups always exchange opinion and learn from each other, influencing the opinion evolution. This paper studies the impacts of interaction among subgroups on the opinion convergence and its stability in the dynamic group decisionmaking. The rules of opinion interaction among individuals within the same subgroup and between different subgroups are setup. Then, a model is presented to describe the dynamic opinion evolution in considering the interactions. With the model, simulation analysis is carried out. Results indicate that the interaction among subgroups promotes achievement of opinion consensus. The higher the mutual confidence level among the subgroups is, the faster the opinion converges, and the higher the stability is. Also, the larger the number of the pieces of opinions flows among the subgroups, the faster the decision making process converges.

Key words:  dynamic group decision making, opinion interaction, convergence