SAILRec: Steering LLM Attention to Dual-Side Semantically Aligned Collaborative Embeddings for Recommendation

Xi Wu, Jiale Wang, Zihan Wang, Yichen Gao, Xiaocui Yang, Shi Feng, Daling Wang, Yifei Zhang


Abstract
Recent LLM-based recommenders enhance language models with collaborative embeddings from user-item interactions, but making such embeddings available does not ensure their proper use during inference. Through a diagnostic attention analysis, we find that the utilization of collaborative embeddings is depth-dependent and alignment-sensitive, suggesting that LLMs need to balance their internal semantic knowledge with external collaborative knowledge. To address this issue, we propose SAILRec, an LLM-based recommender that improves this balance through dual-side semantic alignment and hierarchical attention steering. The former aligns item-side embeddings with item-text semantics and user-side embeddings with codebook-based semantic profiles, while the latter suppresses premature shallow-layer collaborative interference and strengthens collaborative evidence in deeper decision layers. Experiments on MovieLens-1M and Amazon-Book show that SAILRec consistently outperforms representative baselines, with ablation and masking analyses validating its key designs. Our implementation is available at https://github.com/XuPhoenixyear/SAILRec.
Anthology ID:
2026.emnlp-main.1089
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
25013–25033
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1089/
DOI:
Bibkey:
Cite (ACL):
Xi Wu, Jiale Wang, Zihan Wang, Yichen Gao, Xiaocui Yang, Shi Feng, Daling Wang, and Yifei Zhang. 2026. SAILRec: Steering LLM Attention to Dual-Side Semantically Aligned Collaborative Embeddings for Recommendation. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 25013–25033, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
SAILRec: Steering LLM Attention to Dual-Side Semantically Aligned Collaborative Embeddings for Recommendation (Wu et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1089.pdf