Long-term fairness in sequential group recommendations
摘要
Group recommender systems (GRSs) generate recommendations for groups of individuals, making them useful in decision-making scenarios such as friends agreeing on a restaurant, colleagues selecting a team-building activity, or a family choosing a movie for a movie night. Unlike single-user recommender systems, GRS must balance multiple, often conflicting user preferences. A key challenge is ensuring fairness so that no user’s preferences are consistently overlooked. Due to the heterogeneous nature of group members’ preferences, achieving fairness within a single recommendation iteration—sometimes also referred to as a “session”—is not always feasible. However, group decision-making often occurs over a sequence of iterations, providing opportunities to balance fairness over time. In this work, we evaluate existing GRS approaches, applying them in the context of sequential group recommendation, where traditional GRS methods are used across sequence of multiple iterations. Our evaluation also incorporates simulated group choices to better reflect real-world usage scenarios. At the same time, we propose a novel proportionality-preserving approach that improves long-term fairness across iterations while maintaining overall group satisfaction. The source code and additional data are available in the public repository at: https://osf.io/m8z57.