RAH: RecSys-Assistant-Human: The proposed framework placing an LLM assistant between the system and the user.
Proxy Feedback: Synthetic ratings or reviews generated by the LLM assistant on behalf of the user to train the recommender system.
Learn-Act-Critic Loop: An iterative process where the assistant predicts a user's action, validates it against ground truth (Critic), and refines the user profile (Learn) if incorrect.
Cold Start: The difficulty recommender systems face when dealing with new users or items with insufficient interaction data.
Selection Bias: The tendency of users to only rate items they chose to consume (often popular ones), leading to skewed training data.
IPS: Inverse Propensity Scoring—a statistical technique to correct for selection bias by weighting observations inversely to their probability of being observed.
NDCG: Normalized Discounted Cumulative Gain—a measure of ranking quality that takes into account the position of relevant items.
LightGCN: A simplified Graph Convolutional Network for recommendation that learns user/item embeddings via linear propagation.