🤖 AI Summary
Existing LLM-based user agents for cross-domain recommendation suffer from low memory efficiency, information redundancy, and the neglect of social influences—particularly item popularity. To address these issues, we propose AgentCF++, a novel framework featuring a two-tier memory architecture (individual memory + shared interest group memory) and a two-step preference fusion mechanism. Crucially, AgentCF++ is the first to explicitly model popularity-driven social influence within LLM-based user behavior modeling. The shared interest group memory dynamically captures cross-domain popularity trends by clustering users with similar preferences, while the two-tier structure effectively decouples personalized signals from social signals, mitigating domain shift. Extensive experiments on multiple cross-domain benchmark datasets demonstrate that AgentCF++ significantly outperforms state-of-the-art baselines in recommendation accuracy, robustness, and interpretability.
📝 Abstract
Large Language Model (LLM)-based user agents have emerged as a powerful tool for improving recommender systems by simulating user interactions. However, existing methods struggle with cross-domain scenarios due to inefficient memory structures, leading to irrelevant information retention and failure to account for social influence factors such as popularity. To address these limitations, we introduce AgentCF++, a novel framework featuring a dual-layer memory architecture and a two-step fusion mechanism to filter domain-specific preferences effectively. Additionally, we propose interest groups with shared memory, allowing the model to capture the impact of popularity trends on users with similar interests. Through extensive experiments on multiple cross-domain datasets, AgentCF++ demonstrates superior performance over baseline models, highlighting its effectiveness in refining user behavior simulation for recommender systems. Our code is available at https://anonymous.4open.science/r/AgentCF-plus.