Debate, Reflect, and Distill: Multi-Agent Feedback with Tree-Structured Preference Optimization for Efficient Language Model Enhancement

Xiaofeng Zhou, Heyan Huang, Lizi Liao


Abstract
Large Language Models (LLMs) continue to set new standards in knowledge-intensive and complex reasoning tasks, yet their high computational demands limit widespread adoption. While distilling large models into smaller ones offers a sustainable solution, current techniques—such as static knowledge distillation, resource-intensive reinforcement learning from human feedback, or limited self-reflection—struggle to yield substantial and lasting performance gains. In this paper, we present a novel Debate and Reflect (D&R) framework that orchestrates multi-turn debates between smaller models and stronger teacher models, eliciting actionable feedback (e.g., error analysis, corrective strategies) to guide student models. Further, we introduce Tree-structured Direct Preference Optimization (T-DPO) to efficiently leverage these debate logs, organizing interactions into a hierarchical format for effective training. Empirical evaluations across diverse NLP benchmarks demonstrate that our approach significantly improves smaller-model accuracy, robustness, and generalization, outperforming conventional baselines by a large margin.
Anthology ID:
2025.findings-acl.475
Volume:
Findings of the Association for Computational Linguistics: ACL 2025
Month:
July
Year:
2025
Address:
Vienna, Austria
Editors:
Wanxiang Che, Joyce Nabende, Ekaterina Shutova, Mohammad Taher Pilehvar
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
9122–9137
Language:
URL:
https://preview.aclanthology.org/corrections-2025-08/2025.findings-acl.475/
DOI:
10.18653/v1/2025.findings-acl.475
Bibkey:
Cite (ACL):
Xiaofeng Zhou, Heyan Huang, and Lizi Liao. 2025. Debate, Reflect, and Distill: Multi-Agent Feedback with Tree-Structured Preference Optimization for Efficient Language Model Enhancement. In Findings of the Association for Computational Linguistics: ACL 2025, pages 9122–9137, Vienna, Austria. Association for Computational Linguistics.
Cite (Informal):
Debate, Reflect, and Distill: Multi-Agent Feedback with Tree-Structured Preference Optimization for Efficient Language Model Enhancement (Zhou et al., Findings 2025)
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PDF:
https://preview.aclanthology.org/corrections-2025-08/2025.findings-acl.475.pdf