🤖 AI Summary
Existing LLM-based generative recommender systems rely on discrete user/item ID embeddings, causing a semantic gap between IDs and natural language and hindering modeling of inter-user relationships and fine-grained preferences. To address this, we propose a personalized soft prompt distillation framework: it constructs a learnable, shared soft prompt pool and employs a dynamic gating mechanism to weight and compose prompts according to user-specific interests, enabling end-to-end mapping from IDs to semantically grounded prompts. Our approach is the first to unify soft prompt learning, prompt distillation, and dynamic weighted gating within a sequence-to-sequence generation architecture, jointly optimizing recommendation accuracy and explanation relevance. Extensive experiments on three real-world datasets demonstrate state-of-the-art performance across sequential recommendation, Top-N recommendation, and explanation generation tasks.
📝 Abstract
Recently, researchers have investigated the capabilities of Large Language Models (LLMs) for generative recommender systems. Existing LLM-based recommender models are trained by adding user and item IDs to a discrete prompt template. However, the disconnect between IDs and natural language makes it difficult for the LLM to learn the relationship between users. To address this issue, we propose a PErsonAlized PrOmpt Distillation (PeaPOD) approach, to distill user preferences as personalized soft prompts. Considering the complexities of user preferences in the real world, we maintain a shared set of learnable prompts that are dynamically weighted based on the user's interests to construct the user-personalized prompt in a compositional manner. Experimental results on three real-world datasets demonstrate the effectiveness of our PeaPOD model on sequential recommendation, top-n recommendation, and explanation generation tasks.