Using Agent Importance to Combat Preference Manipulation in Group Decision Making

We consider the problem of group decision making where the selection process is based upon a group preference function, obtained by an aggregation of the participating agents individual preference functions. We describe some methods for formulating the group preference from the individual preference functions. We note the possibility of the individual agents strategically manipulating the information they provide, so as to further their own goal of getting their most preferred alternative selected by the group. With this in mind, we suggest ways of modifying the formulation of the group decision functions to discourage strategic manipulation by the participating agents.

The paper reports on an exploratory study of student spontaneous group decision making (GDM) in distributed collaborative learning environments. Recordings of group meetings were collected from graduate students working on a database design project (in a library and information science program in California), from which group decision instances were extracted and formally coded for quantitative analysis. A follow-up survey was conducted to gather more information. The study finds that students are generally in favor of an unfacilitated and semi-structured GDM process, with group decisions typically made by consensus. A rigidly structured GDM process tends to be associated with poor group performance. GDM efficiency is an important predictor of the quality of final group products, and too much brainstorming may lead to difficulties. Students relying exclusively on text chatting tend to be unsure if their opinion was given equal attention, and those in underperforming groups are more doubtful about decision quality.

Many of the most important decisions in our society are made within groups, yet we know little about how the physiological responses of group members predict the decisions that groups make. In the current work, we examine whether physiological linkage from “senders” to “receivers”—which occurs when a sender’s physiological response predicts a receiver’s physiological response—is associated with senders’ success at persuading the group to make a decision in their favor. We also examine whether experimentally manipulated status—an important predictor of social behavior—is associated with physiological linkage. In groups of 5, we randomly assigned 1 person to be high status, 1 low status, and 3 middle status. Groups completed a collaborative decision-making task that required them to come to a consensus on a decision to hire 1 of 5 firms. Unbeknownst to the 3 middle-status members, high- and low-status members surreptitiously were told to each argue for different firms. We measured cardiac interbeat intervals of all group members throughout the decision-making process to assess physiological linkage. We found that the more receivers were physiologically linked to senders, the more likely groups were to make a decision in favor of the senders. We did not find that people were physiologically linked to their group members as a function of their fellow group members’ status. This work identifies physiological linkage as a novel correlate of persuasion and highlights the need to understand the relationship between group members’ physiological responses during group decision-making.

Group decision-making, in which a collective decision needs to be derived from individual agents’ preferences has been an active area of research. In group decisionmaking, autonomous agents need some procedures or mechanisms that can collect preference information from them and make a decision; or some protocols that enable them to be involved in the decision process, to interact with each other and to jointly make a collective decision. Examples include preference aggregation mechanisms, negotiation protocols, voting procedures, and auctions. This thesis studies the problem of agent-based group decision-making in various problem settings, proposing several efficient approaches to support multiple agents in reaching efficient and fair collective decisions overmultiple issues. The research work in this thesis can be divided into two parts, addressing the agent-based group decision-making problem in circumstances in which there is, respectively, complete and incomplete information available. The first part of this thesis focuses on preference aggregation in combinatorial domains, provided all agents’ preferences. Structured preferences Conditional Preference Network (CP-nets) and its variant Trade-off enhanced CP-nets (TCP-nets) are used as formal models for representing the agents’ preferences in group decision-making. Before going into the problem of making a group decision from a collection of CP-nets or TCP-nets, the problem of individual preference reasoning is studied and a computationally efficient heuristic algorithm for dominance testing in CP-nets, which forms the basis for many group decision-making mechanisms, is introduced. Subsequently, we consider the group decision-making problem with multiple agents’ CP-nets and TCP-nets. As the space of possible outcomes in combinatorial domains has a size exponential in the number of variables, computational complexity in group decision-making will be one of the issues that need to be addressed. Two computationally efficient approaches are proposed in order to support agent-based group decisionmaking in combinatorial domains with different decision criteria: (i) an approach that converts the qualitative preferences derived from CP-nets or TCP-nets into numerical penalty scoring functions, and then searches for an optimal collective decision based on the individual penalty scores; and (ii) an approach that focuses on combinatorial vote and computes the winners (i.e., winning alternatives) from a collection of CP-nets according to Majority voting rule. The second part of this thesis is concerned with the disadvantage of disclosing preference information in group decision-making and considers the incomplete information setting. Two negotiation approaches are presented in order to support agent-based group decision-making in, respectively, combinatorial domains and in domains with multiple continuous issues. Firstly, a negotiation protocol in combinatorial domains is proposed, which enables agents to distributively make decisions and leads them to Pareto-optimal agreements under incomplete information setting. Then for the domains with multiple continuous issues, a cooperative mediated negotiation approach is proposed to support the agents searching for joint utility gains and reaching an efficient and fair agreement. For every approach introduced in this thesis, experiments are carried out and the results are presented and analysed in order to provide insights into the performance of these approaches.

Outcome evaluations in group decision-making using authority rule: An electrophysiological study

<p>This thesis investigates the group decision-making process of Chinese international students travelling with friends in New Zealand. Focusing on groups of friends, a neglected decision-making unit, it explores models of group decision-making and disagreement prevention and resolution strategies of Chinese international students making travel-related decisions. Qualitative research method governed by the interpretive paradigm was adopted. Sixteen Chinese international students from Victoria University of Wellington were interviewed. They were from eleven travel groups and had experience of independent leisure travel in non-family groups in New Zealand. Given that Chinese independent visitor market to New Zealand keeps growing, and Chinese international students have been referred as “China's first wave of independent travellers” (King & Gardiner, 2015), this study adds knowledge to the understanding of the travel behaviours and decision-making process of this market travelling in New Zealand. Tourism attractions were the most discussed travel-related decision during the group decision-making process, followed by decisions on travel activities, food and restaurants, accommodation and transportation. Three group decision-making models were identified: leadership, division of work, and shared decision-making. Leadership includes three roles of leaders, namely the travel initiator who has the initial idea for the trip and who gets potential members together, the main plan-provider who is responsible for collecting travel information and travel tips to make the whole travel plan and arrange travel schedules, and the main decision-maker who makes the final decision in the travel group. The former two roles are with less dominance, while the latter is with higher dominance in the decision-making process. The division of work model refers to dividing the tasks (e.g. organising accommodation or transport) within the travel group and includes two roles: the plan-provider who is responsible for making the plan for the allocated task, and the decision-maker who made the decision on the allocated task. In the shared decision-making model, the group members make the travel-related decisions collectively by discussion and voting. Most travel groups were found to use multiple group decision-making models conjointly, with a few groups only using the shared decision-making model. Overall, the most used models were shared decision-making and leadership. Most travel group who adopted the leadership model tended to then use either shared decision-making model or the division of work model depending on the level of dominance of group leader. Most interviewees indicated that there was lack of disagreement during the group decision-making process. Thus the research focus has shifted from the disagreement resolution to the disagreement prevention. Five disagreement prevention strategies and one influencing factor were identified: travelling with like-minded people, adequate preparation, empathy and mutual understanding, tolerance, compensation and external factors. If disagreements occurred, one or more of tight strategies were adopted by the interviewees to resolve them, namely making concessions, discussing and voting, looking for alternatives, persuasion, toleration, splitting up, accommodating and delaying. Implications and recommendation for industries and future studies are discussed.</p>

Multi criteria decision making (MCDM) and group decision making (GDM) are two well practiced approaches to solve decision making problems. Group decision making combines opinions from Decision makers (DMs) into a coherent group decision. The aim of this paper is to develop a new fuzzy group decision making algorithm and apply it to a real-world groundwater development problem to select the most preferred alternative. Five decision makers (DMs) are selected to express their judgments about relative importance of 3 criteria (water pumped, cost, and risk) and have given their preferences as ordinal preferences, utility values, fuzzy preference relations and multiplicative preference relations. Decision makers' opinions are aggregated based on a fuzzy group decision making. Ordered weighted averaging (OWA) operator has been used to aggregate decision makers' opinions. Consensus measure is also defined to evaluate convergence between group and individual opinions. The outcomes of the proposed algorithm show that proposed fuzzy group decision making process is a relevant approach to aggregate the individual expert's opinion and is a desirable tool to reach consensus among DMs.

This paper presents a novel and comprehensive classification mechanism that groups numerous dimensions associated with group decision-making approaches. We identify three broad categorizations of group decision-making literature. The classified dimensions are clustered by whether they are intrinsic to the group of participants, the nature of the addressed problems (topics), or a choice in the decision process design. We highlight the unique challenges facing manual group decision-making and those linked with intelligent support for group decision-making. Manual rules governing traditional face-to-face meetings must be adapted to suit virtual meetings where co-decisions must be made electronically. Virtual group decision-making for large groups facilitated by the extensive use of social media tools is an emergent area that has proven to be a necessity that has had a tremendous influence on society for the whole world during the recent Covid-19 pandemic. We first present the associated challenges, followed by the potential solution of computer-based group decision-making systems. We further discuss binary and multi-features of group decision approaches with justifications and examples. Communication has been identified as the main bottleneck, and various attacks have been revealed. This research opens up several aspects of group decision-making that could be further studied. For example, a cluster of dimensions concerns the truthfulness of the information exchanged and how untruthfulness is handled, starting with detection and how to react to detected lies. The scale of technology-supported group decision-making has grown to the point where its influence has been accused or lauded in the last few US elections. There is a persistent call for properties such as transparency and fairness in group decision-making systems.

This paper seeks to prove that under a large class of group decision rules some sincere voting situations will be unstable because of strategic manipulation by single individuals. The concept of stability used is weaker than the stability concepts figuring in many earlier contributions in this area, insofar as under the concept used here any individual, while disrupting a given voting situation, considers the possibility of retaliation by other individuals. DUMMETT AND FARQUHARSON [2], Murakami [7], Farquharson [3], Sen [14], Gibbard [4], Satterthwaite [13], and Pattanaik [10, 11, and 12] have discussed various aspects of the problem of stability in voting. The general conclusion which emerges from these writings seems to be that stability of all possible sincere voting situations (which implies the absence of strategic distortion of preferences by voters) is an extremely rare feature of democratic group decision procedures. However, the notion of stability or equilibrium underlying many of these contributions is a simple one and does not take into account several phenomena usually associated with strategic voting such as the possibility of counter-coalitions when a coalition (of one or more individuals) threatens to disrupt a voting situation. The purpose of this paper is twofold. First, it introduces a less demanding notion of stability which takes into account the possibility of formation of countercoalitions when an individual seeks to influence the outcome in his own favor by strategic manipulations in voting. Secondly, using this very weak notion of stability, it is shown that, while under the changed definition the possibility of having unstable sincere voting situations because of strategic voting by single individuals is somewhat reduced, invulnerability of all possible sincere voting situations to voting maneuvres of single individuals still remains a very rare property among democratic group decision rules based on pairwise comparisons. We lay down the basic notation and some preliminary definitions in Section 1. In Section 2 we introduce a notion of stability taking into account the possibility of counter-coalitions. Using this very weak definition of stability, in Section 3 we show that under most democratic group decision rules based on pairwise comparisons, there is the danger of having unstable sincere voting situations owing to strategic manipulations by single individuals. We conclude in Section 4.

This study proposes a group decision making (GDM) method with preference analysis to re-build the Global Entrepreneurship Index (GEI). Specifically, a single decision maker is firstly identified using a specified individual judgement about the importance order of three sub-indices of the GEI. A preliminary group decision matrix is constructed in terms of taking all possible individual judgments into account. Then the analysis of the preferential differences and preferential priorities with respect to the preliminary group decision matrix is conducted to obtain a revised group decision matrix, in which preferential differences calculate the weighted differences as the degrees of differences among different alternatives for each decision maker, preferential priorities describe the favorite ranking of alternatives for each decision maker. Finally, we employ the Stochastic Multicriteria Acceptability Analysis for group decision-making (SMAA-2) to create the holistic acceptability indices for measuring the entrepreneurship performance. In addition, a satisfaction index is developed to indicate the merits of proposed GDM method. A case study using the GEI-2019 of 19 G20 countries is carried out to validate our GDM method.

A hesitation-feedback recommendation approach and its application in large-scale group emergency decision making

12 - An observational experiment in group decision-making: Can people detect bad group decisions?

Group decision processes: MOLP procedures facilitating group and individual decision orientations

The essential goal of corporate finance is to maximize corporate value while reducing a firm’s financial risks. Corporate financing decision is a kind of multi-criteria based group decision making that embodies major approaches to handle qualitative criteria and quantitative limitations. However, in literature related to financing decision making, very little research uses decision making trial and evaluation laboratory (DEMATEL) and analytic network process (ANP) methods to consider the impact and dependency of its factors, or uses Goal programming (GP) to find the satisfactory financing decision under the related financial constraints. This study proposes an integrated group decision making support (GDMS) model to assist corporate financing group decision makers (DMs) in obtaining a satisfactory group solution. ANP, DEMATEL and GP are combined in this GDMS model. By using this model, the group DMs can systemically structure a multi-criteria network framework and derive priority weights of those criteria, and then deal with the quantitative financial constraints for a satisfactory group solution. An illustrative case is demonstrated for the effectiveness and practicability of this GDMS model.

The amount of land for the current location of housing development has resulted in developers choosing the location of housing development regardless of the condition of the land, infrastructure, socio-economic. To overcome this problem a computer system is needed in the form of a GDSS that can assist in the selection of Housing Development Locations.This study aims to implement a GDSS with ANP and Borda methods to determine the selection of the right and fast housing development location. GDSS is needed because there are 3 Individual Decision Makers, DM-1 assessing based on Land Conditions, DM-2 assessing Infrastructure-based, DM-3 assess the Socio-Economic and Decision Maker based groups to make the final decision. The ANP method is used to weight the criteria from each alternative location, to the alternative ranking of housing construction locations for each individual Decision Maker. The Borda method is used to combine the results of ranking carried out by the Group Decision Maker so that it gets the final ranking as a determinant of the Location of Housing Development.The final result of this research is a decision support system that can help developers to get a priority recommendation according to the needs of the developer.