What Makes LLMs Effective Sequential Recommenders? A Study on Preference Intensity and Temporal Context

Fuente: arXiv
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Auteurs principaux: Ouyang, Zhongyu, Wen, Qianlong, Zhang, Chunhui, Ye, Yanfang, Vosoughi, Soroush
Format: Preprint
Publié: 2025
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author Ouyang, Zhongyu
Wen, Qianlong
Zhang, Chunhui
Ye, Yanfang
Vosoughi, Soroush
author_facet Ouyang, Zhongyu
Wen, Qianlong
Zhang, Chunhui
Ye, Yanfang
Vosoughi, Soroush
contents What enables large language models (LLMs) to effectively model user preferences in sequential recommendation? Our investigation reveals that existing preference-alignment approaches largely rely on binary pairwise comparisons, overlooking two critical factors: preference intensity (the structured strength of affinity or aversion) and temporal context (the extent to which recent interactions better reflect a user's current intent). Through controlled experiments, we show that leveraging comprehensive feedback with structured preference signals substantially improves recommendation performance, indicating that binary modeling discards essential information. Motivated by these findings, we propose RecPO, a unified preference optimization framework that maps both explicit and implicit feedback into a common preference signal and constructs adaptive reward margins that jointly account for preference intensity and interaction recency. Experiments across five datasets show that RecPO consistently outperforms state-of-the-art baselines while exhibiting behavioral patterns aligned with human decision-making, including favoring immediate satisfaction, maintaining preference coherence, and avoiding dispreferred items. Our results highlight that preference intensity and temporal context are fundamental ingredients for effective LLM-based recommendation.
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id arxiv_https___arxiv_org_abs_2506_02261
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle What Makes LLMs Effective Sequential Recommenders? A Study on Preference Intensity and Temporal Context
Ouyang, Zhongyu
Wen, Qianlong
Zhang, Chunhui
Ye, Yanfang
Vosoughi, Soroush
Information Retrieval
Machine Learning
What enables large language models (LLMs) to effectively model user preferences in sequential recommendation? Our investigation reveals that existing preference-alignment approaches largely rely on binary pairwise comparisons, overlooking two critical factors: preference intensity (the structured strength of affinity or aversion) and temporal context (the extent to which recent interactions better reflect a user's current intent). Through controlled experiments, we show that leveraging comprehensive feedback with structured preference signals substantially improves recommendation performance, indicating that binary modeling discards essential information. Motivated by these findings, we propose RecPO, a unified preference optimization framework that maps both explicit and implicit feedback into a common preference signal and constructs adaptive reward margins that jointly account for preference intensity and interaction recency. Experiments across five datasets show that RecPO consistently outperforms state-of-the-art baselines while exhibiting behavioral patterns aligned with human decision-making, including favoring immediate satisfaction, maintaining preference coherence, and avoiding dispreferred items. Our results highlight that preference intensity and temporal context are fundamental ingredients for effective LLM-based recommendation.
title What Makes LLMs Effective Sequential Recommenders? A Study on Preference Intensity and Temporal Context
topic Information Retrieval
Machine Learning
url https://arxiv.org/abs/2506.02261