Recommender systems (RecSys) have been well developed to assist user decision making. Traditional RecSys usually optimize a single objective (e.g., rating prediction errors or ranking quality) in the model. There is an emerging demand in multi-objective optimization recently in RecSys, especially in the area of multi-stakeholder and multi-task recommender systems. This article provides an overview of multi-objective recommendations, followed by the discussions with case studies. The document is considered as a supplementary material for our tutorial on multi-objective recommendations at ACM SIGKDD 2021.

翻译：推荐系统（RecSys）已得到良好发展，用以辅助用户决策。传统推荐系统通常在模型中优化单一目标（如评分预测误差或排序质量）。近年来，推荐系统领域对多目标优化的需求日益凸显，尤其是在多利益相关者和多任务推荐系统中。本文概述了多目标推荐，并结合案例研究进行讨论。本文档可作为我们于ACM SIGKDD 2021上关于多目标推荐的教程的补充材料。