Beyond Query-Item Matching: Personalized Behavioral Relevance Modeling for E-commerce Search via Rubric-Guided Reinforcement Learning

Yang Liu, Chenxu Wang, Jianzhi Shao, Jun Ji, Xiaozhou Xu, Zhe Sun, Wei Hu


Abstract
E-commerce search systems typically separate query-item relevance matching from downstream personalized ranking. While effective for large-scale serving, this design leaves relevance levels dominated by objective query-item matching, forcing follow-up ranking to operate over candidate structures that may not reflect user behavioral preference. We define a new personalized behavioral relevance task, which predicts whether a relevance-stage candidate item is supported by the user’s behavioral evidence under current query intent. We develop a corresponding framework, BRIDGE, for Behavioral Relevance Inference with Dynamic Guidance from Evidence. It organizes multi-timescale behavioral context from online logs, obtains reliable supervision with multi-perspective annotation and adjudication, and trains an LLM to produce structured evidence-grounded decision rationales. It particularly incorporates sample-specific rubric rewards into GRPO to improve generated reasoning traces. Offline experiments validate that BRIDGE improves both prediction accuracy and reasoning quality. Online A/B tests show gains of 0.19% in active user-days and 0.67% in transaction-related user-days, both significant in statistics.
Anthology ID:
2026.emnlp-industry.86
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Pepa Atanasova, Gholamreza Haffari, Minghan Wang
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
1444–1455
Language:
URL:
https://aclanthology.org/2026.emnlp-industry.86/
DOI:
Bibkey:
Cite (ACL):
Yang Liu, Chenxu Wang, Jianzhi Shao, Jun Ji, Xiaozhou Xu, Zhe Sun, and Wei Hu. 2026. Beyond Query-Item Matching: Personalized Behavioral Relevance Modeling for E-commerce Search via Rubric-Guided Reinforcement Learning. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track, pages 1444–1455, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Beyond Query-Item Matching: Personalized Behavioral Relevance Modeling for E-commerce Search via Rubric-Guided Reinforcement Learning (Liu et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-industry.86.pdf