Towards Social Choice-based Explanations in Group Recommender Systems

Thi Ngoc Trang Tran, Müslüm Atas, Alexander Felfernig, Viet Man Le, Ralph Samer, Martin Stettinger

Research output: Chapter in Book/Report/Conference proceedingConference paperpeer-review


Explanations help users to better understand why a set of items has been recommended. Compared to single user recommender systems, explanations in group recommender systems have further goals. Examples thereof are fairness which helps to take into account as much as possible group members' preferences and consensus which persuades group members to agree on a decision. This paper proposes different explanation types and investigates which explanation best helps to increase the fairness perception, consensus perception, and satisfaction of group members with regard to group recommendations. We conducted a user study to evaluate the proposed explanations. The results show that explanations which take into account preferences of all or the majority of group members achieve the best results in terms of the mentioned aspects. Moreover, there exist positive correlations among these aspects, i.e., as the perceived fairness (or the perceived consensus) of explanations increases, so does the satisfaction of users with regard to group recommendations. In addition, in the context of repeated decisions, the inclusion of group members' satisfaction from previous decisions in the explanations helps to improve the fairness perception of users with regard to group recommendations.
Original languageEnglish
Title of host publicationUMAP '19: Proceedings of the 27th ACM Conference on User Modeling, Adaptation and Personalization
Place of PublicationLarnaca, Cyprus
Number of pages9
ISBN (Print)978-1-4503-6021-0
Publication statusPublished - 2019
Event27th ACM Conference on User Modeling, Adaptation and Personalization - Larnaca, Cyprus
Duration: 9 Jun 201912 Jun 2019


Conference27th ACM Conference on User Modeling, Adaptation and Personalization
Abbreviated titleUMAP 2019


  • social choice
  • preference aggregation strategies
  • explanations
  • group decision making
  • group recommender systems
  • social factors
  • fairness perception
  • consensus perception
  • satisfaction

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