Improving consensus in social network group decision-making: Emphasizing overlapping subgroups and interactive behaviors

The multilevel nature of social networks and the multiple identities of decision makers (DMs) have led to the co-existence of overlapping and non-overlapping subgroups in social network group decision-making. This paper focuses on three issues in an intuitionistic fuzzy environment in this situation. Firstly, some unknown trust relationships exist between DMs belonging to different subgroups. Secondly, interactions between DMs and subgroups affect the final consensus result. Thirdly, opinions of DMs belonging to multiple subgroups simultaneously (i.e., key DMs) affect the opinions of these overlapping subgroups to varying degrees. To address the first issue, a trust propagation operator considering trust influence and trust decay is proposed to estimate the trust values between DMs belonging to different subgroups. To solve the second issue, we describe interactions within and between subgroups by factors such as trust value and overlapping level. To manage the third issue, we introduce the Choquet integral to gather opinions and construct an interactive behavior-driven hierarchical consensus model to obtain the group opinion for the non-additive interactions between DMs and subgroups. Finally, the effectiveness and applicability of the method are verified through illustrative examples and comparisons.