JIIS preface for the special issue on advances in recommender systems

Recommender systems have been successfully applied to alleviate overloaded information and assist decision making in various domains and applications. Recently, several new research directions emerged and novel techniques were proposed to advance the development of recommender systems. In this special issue, we invited authors to submit the revised and extended version of their accepted papers in the track on recommender systems associated with ACM Symposium on Applied Computing in 2020 and 2021. Each submission was reviewed by at least two experts and revised according to the reviewers' comments to ensure the quality of the paper. We hope this special issue can motivate researchers in the area of recommender systems to take the next step beyond traditional algorithm development and seek more opportunities in their research work.