Align, Don’t Fuse: Structure-Preserving Alignment of Collaborative and Semantic Signals for LLM-Enhanced Recommendation

Jooweon Choi, MiHyeon Kim, Eunju Lee, Junehyoung Kwon, YoungBin Kim


Abstract
Large Language Models (LLMs) provide rich semantic representations for recommender systems, but their semantic similarity may not align with collaborative preference patterns captured by collaborative filtering (CF). Directly combining LLM and CF representations can therefore distort the structural relationships encoded in the interaction graph. We propose Structure-Preserving Alignment (SPA), which reformulates CF–LLM integration as language-supervised representation alignment. SPA derives collaborative anchors from frozen CF representations and aligns multiple LLM-generated semantic views toward these anchors through cross-profile view competition. The aligned collaborative representations are then used for structure-preserving two-channel retrieval, which constructs behavior-aware context for downstream LLM-based preference prediction. Experiments on multiple datasets and CF backbones show that SPA consistently improves click-through rate (CTR)-style binary preference prediction.
Anthology ID:
2026.findings-emnlp.356
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
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SIGDAT
Publisher:
Association for Computational Linguistics
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Pages:
7444–7479
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URL:
https://aclanthology.org/2026.findings-emnlp.356/
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Cite (ACL):
Jooweon Choi, MiHyeon Kim, Eunju Lee, Junehyoung Kwon, and YoungBin Kim. 2026. Align, Don’t Fuse: Structure-Preserving Alignment of Collaborative and Semantic Signals for LLM-Enhanced Recommendation. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 7444–7479, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Align, Don’t Fuse: Structure-Preserving Alignment of Collaborative and Semantic Signals for LLM-Enhanced Recommendation (Choi et al., Findings 2026)
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https://aclanthology.org/2026.findings-emnlp.356.pdf