Rethinking Role-Playing Evaluation: Anonymous Benchmarking and A Systematic Study of Personality Effects

Ji-Lun Peng, Yun-Nung Chen


Abstract
Large Language Models (LLMs) have shown remarkable potential in developing role-playing agents (RPAs). However, current evaluation frameworks rely heavily on well-known fictional characters, raising a critical concern: models may be leveraging their internal training memory of these characters rather than demonstrating role-playing capabilities. This reliance often leads to significant performance degradation when RPAs encounter unseen or out-of-distribution personas. To address this, we propose a more rigorous evaluation protocol designed to decouple role-playing proficiency from character recognition. Our experiments across multiple benchmarks demonstrate that anonymizing characters degrades performance, confirming that name exposure provides implicit cues that mask a model’s true capability. To mitigate this, we investigate diverse personality augmentation as a method to enhance role fidelity in anonymous settings. We systematically analyze the impact of various personality-description methods on agent behavior and consistency. Our results show that incorporating personality information consistently improves RPA performance. This work establishes a more equitable evaluation standard and validates a scalable, personality-enhanced framework for constructing robust RPAs.
Anthology ID:
2026.sigdial-1.15
Volume:
Proceedings of the 27th Annual Meeting of the Special Interest Group on Discourse and Dialogue
Month:
August
Year:
2026
Address:
Atlanta, Georgia, USA
Editors:
Jinho D. Choi, Yun-Nung Chen, Kotaro Funakoshi, Ali Emami
Venue:
SIGDIAL
SIG:
SIGDIAL
Publisher:
Association for Computational Linguistics
Note:
Pages:
205–218
Language:
URL:
https://aclanthology.org/2026.sigdial-1.15/
DOI:
Bibkey:
Cite (ACL):
Ji-Lun Peng and Yun-Nung Chen. 2026. Rethinking Role-Playing Evaluation: Anonymous Benchmarking and A Systematic Study of Personality Effects. In Proceedings of the 27th Annual Meeting of the Special Interest Group on Discourse and Dialogue, pages 205–218, Atlanta, Georgia, USA. Association for Computational Linguistics.
Cite (Informal):
Rethinking Role-Playing Evaluation: Anonymous Benchmarking and A Systematic Study of Personality Effects (Peng & Chen, SIGDIAL 2026)
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PDF:
https://aclanthology.org/2026.sigdial-1.15.pdf