L2Rec: Towards Dual-View Understanding of LLMs for Personalized Recommendation
L2Rec:面向个性化推荐的LLM双视图理解
Pingjun Pan, Tingting Zhou, Peiyao Lu, Tingting Fei, Hongxiang Chen, Chuanjiang Luo
AI总结 提出L2Rec方法,通过双视图个性化混合专家机制在参数层面统一行为与语义理解,实现端到端个性化推荐,实验证明优于现有方法。
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- Accepted at SIGIR 2026
将大型语言模型(LLM)适配于个性化推荐需要将其通用能力与用户特定偏好对齐,同时有效利用行为信号和语义信号。现有方法通常在输入层(例如,将行为嵌入注入令牌空间)或输出层(例如,独立编码器的对比对齐)整合这些信号,存在分布差距或缺乏端到端任务监督。在这项工作中,我们引入了L2Rec,它在LLM的参数层面统一了行为和语义理解。我们的关键洞察是,同一组Transformer参数可以作为两个视图的共享媒介:通过双视图个性化混合专家(DPMoE)机制应用视图特定的个性化低秩扰动,L2Rec使得单个LLM主干能够为每个用户产生互补的行为和语义适应,且表示层面的不对齐最小化。一个自适应跨视图融合模块进一步将双视图输出整合为统一的用户偏好。在四个数据集上的实验表明,L2Rec持续优于最先进的基线方法,并且在大型工业平台上的在线A/B测试验证了关键参与指标的显著改进。
Adapting large language models (LLMs) for personalized recommendation requires aligning their general-purpose capabilities with user-specific preferences while effectively leveraging both behavioral and semantic signals. Existing approaches typically integrate these signals at either the input level (e.g., injecting behavioral embeddings into the token space) or the output level (e.g., contrastive alignment of separate encoders), suffering from distribution gaps or lack of end-to-end task supervision. In this work, we introduce L2Rec, which unifies behavioral and semantic understanding at the parameter level of LLMs. Our key insight is that the same set of Transformer parameters can serve as a shared medium for both views: by applying view-specific, personalized low-rank perturbations via a Dual-view Personalized Mixture-of-Experts (DPMoE) mechanism, L2Rec enables a single LLM backbone to produce complementary behavioral and semantic adaptations for each user with minimal representation-level misalignment. An adaptive cross-view fusion module further integrates the dual-view outputs into a unified user preference. Experiments on four datasets show that L2Rec consistently outperforms state-of-the-art baselines, and online A/B testing on a large-scale industrial platform validates significant improvements in key engagement metrics.