PLASTIC: Prioritize Long and Short-term Information in Top-n Recommendation using Adversarial Training

Recommender systems provide users with ranked lists of items based on individual’s preferences and constraints. Two types of models are commonly used to generate ranking results: long-term models and session-based models. While long-term models represent the interactions between users and items that are supposed to change slowly across time, session-based models encode the information of users’ interests and changing dynamics of items’ attributes in short terms. In this paper, we propose a PLASTIC model, Prioritizing Long And ShortTerm Information in top-n reCommendation using adversarial training. In the adversarial process, we train a generator as an agent of reinforcement learning which recommends the next item to a user sequentially. We also train a discriminator which attempts to distinguish the generated list of items from the real list recorded. Extensive experiments show that our model exhibits significantly better performances on two widely used datasets.1