Distilling LLM Reasoning into an Interpretable Policy Tree for Human-AI Collaboration

Beiwen Zhang, Yongheng Liang, Guowei Zou, Haitao Wang, Hejun Wu


Abstract
Constructing efficient and reliable policies to assist humans is indispensable for human-AI collaboration. Existing methods mainly follow two lines of work. The majority of prior work relies on multi-agent reinforcement learning (MARL) to learn black-box policies, which limits interpretability and raises safety concerns. Recent methods query large language models (LLMs) at each decision step, causing slow responses and high inference costs. We propose Co-𝜋-tree, a closed-loop method that learns an executable policy tree consisting of a partner-behavior prediction tree and an agent-action selection tree. Co-𝜋-tree constructs a policy through distilling LLM reasoning into policy tree code. It then evaluates the policy through partner interaction, obtains feedback, and uses natural language summaries of interaction feedback to improve problematic branches. Experiments in Overcooked-AI show that Co-π-tree improves average reward by 6.4% over the strongest LLM baseline, while reducing the number of LLM queries by 77.7% and test-time latency by 97.1%. Project page: https://beiwenzhang.github.io/Co-pi-tree/.
Anthology ID:
2026.findings-emnlp.884
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:
18661–18682
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.884/
DOI:
Bibkey:
Cite (ACL):
Beiwen Zhang, Yongheng Liang, Guowei Zou, Haitao Wang, and Hejun Wu. 2026. Distilling LLM Reasoning into an Interpretable Policy Tree for Human-AI Collaboration. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 18661–18682, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Distilling LLM Reasoning into an Interpretable Policy Tree for Human-AI Collaboration (Zhang et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.884.pdf