Report on the Workshop on Learning and Evaluating Recommendations with Impressions (LERI) at RecSys 2023

The Workshop on Learning and Evaluating Recommendations with Impressions (LERI) was held in conjunction with the 17th ACM Conference on Recommender Systems (RecSys 2023). The program included a keynote, a panel discussion and 7 paper presentations. The proceedings of the workshop are available online.1 The LERI workshop focused on all aspects related to the use of impressions for recommendation with the aim to bring the community together and share experience and perspectives. Recommender systems typically rely on past user interactions as the primary source of information for making predictions. Impressions are an important source of information that indicate the items displayed on screen when the user interacted (or not) with them, and have the potential to impact the field of recommender systems in several ways. Impressions present new research questions and opportunities, but also bring new challenges. Date: 19 September 2023. Website: https://recsyspolimi.github.io/leri2023/.