EpiPersona: Persona Projection and Episode Coupling for Pluralistic Preference Modeling

Yujie Zhang, Weikang Yuan, Zhuoren Jiang, Pengwei Yan


Abstract
Pluralistic alignment is essential for adapting large language models (LLMs) to the diverse preferences of individuals and minority groups. However, existing personalized reward models often mix stable personal traits with episode-specific factors, limiting their ability to generalize across episodes. To address this challenge, we propose EpiPersona, a framework for explicit persona–episode coupling. EpiPersona first projects noisy preference feedback into a low-dimensional persona space, where similar personas are aggregated into shared discrete codewords. This process separates enduring personal characteristics from situational signals without relying on predefined preference dimensions. The inferred persona representation is then coupled with the current episode, enabling episode-aware preference prediction. Extensive experiments show that EpiPersona outperforms the baselines. It achieves notable performance gains in hard episodic-shift scenarios, while remaining effective with sparse preference data.
Anthology ID:
2026.emnlp-main.2413
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:
54804–54823
Language:
URL:
https://aclanthology.org/2026.emnlp-main.2413/
DOI:
Bibkey:
Cite (ACL):
Yujie Zhang, Weikang Yuan, Zhuoren Jiang, and Pengwei Yan. 2026. EpiPersona: Persona Projection and Episode Coupling for Pluralistic Preference Modeling. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 54804–54823, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
EpiPersona: Persona Projection and Episode Coupling for Pluralistic Preference Modeling (Zhang et al., EMNLP 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.emnlp-main.2413.pdf