LLM-Summarized Interest Distillation for Multimedia Recommendation

Abstract

Recommendation system technology faces the fundamental challenge of data sparsity. Although incorporating auxiliary textual data works to enrich interactions, lengthy and unstructured item descriptions often fail to depict user interests, as they primarily describe item attributes. Furthermore, the sparse interactions provide incomplete interest patterns, leading to biased recommendations. To address these issues, this work proposes an LLM-summarized interest distillation (SID) model to enrich interactions by interest summarization and retrieval augmentation. Interest summarization leverages large language model to improve user interest descriptions and filters out interest-irrelevant details, generating compact, user-centric interest texts. Retrieval augmentation utilizes semantic neighbors as multiple teachers to adaptively transfer their multimodal collaborative knowledge to augment behaviorally sparse student users, thereby enriching interest learning for recommendation. It enhances interactions both qualitatively, through improved interest descriptions, and quantitatively, through expanded semantic neighbors. Extensive experiments show the superior performance of SID over the state-of-the-art models, demonstrating its effectiveness of interest summarization and retrieval augmentation to improve recommendations.