Scalable Multi-Agent LLMs for Multi-Turn Conversation Bias Detection and Mitigation

Victor H. Vargas, Farsheed Haque, Depeng Xu, Xi Niu


Abstract
Large language models (LLMs) increasingly participate in conversational systems where responses emerge through multi-turn interactions rather than single prompts. We introduce a multi-agent evaluation framework that probes LLMs for bias through multi-turn conversations. We present a framework that orchestrates three roles (target, adversary, and scorer) under diverse normative fairness definitions. Experiments on five widely used LLMs using 100 adversarial prompts show that adversarial multi-turn probing reliably surfaces bias-related responses, with baseline violation rates exceeding 80% across models, while human validation with the scorer (~85% agreement) confirms the scoring reliability. Preventive prompt-conditioning strategies provide limited reduction in violations, while our iterative post-hoc mitigation pipeline substantially reduces scorer-detected violations under the active fairness profile, from over 80% to near-zero. We frame this as scorer-relative violation reduction rather than universal debiasing.
Anthology ID:
2026.findings-emnlp.1314
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
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
27827–27843
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1314/
DOI:
10.18653/2026.findings-emnlp.1314
Bibkey:
Cite (ACL):
Victor H. Vargas, Farsheed Haque, Depeng Xu, and Xi Niu. 2026. Scalable Multi-Agent LLMs for Multi-Turn Conversation Bias Detection and Mitigation. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 27827–27843, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Scalable Multi-Agent LLMs for Multi-Turn Conversation Bias Detection and Mitigation (Vargas et al., Findings 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.findings-emnlp.1314.pdf