Watch Every Step! LLM Agent Learning via Iterative Step-level Process Refinement

Weimin Xiong, Yifan Song, Xiutian Zhao, Wenhao Wu, Xun Wang, Ke Wang, Cheng Li, Wei Peng, Sujian Li


Abstract
Large language model agents have exhibited exceptional performance across a range of complex interactive tasks. Recent approaches have utilized tuning with expert trajectories to enhance agent performance, yet they primarily concentrate on outcome rewards, which may lead to errors or suboptimal actions due to the absence of process supervision signals. In this paper, we introduce the **I**terative step-level **P**rocess **R**efinement **(IPR)** framework, which provides detailed step-by-step guidance to enhance agent training. Specifically, we adopt the Monte Carlo method to estimate step-level rewards. During each iteration, the agent explores along the expert trajectory and generates new actions. These actions are then evaluated against the corresponding step of expert trajectory using step-level rewards. Such comparison helps identify discrepancies, yielding contrastive action pairs that serve as training data for the agent. Our experiments on three complex agent tasks demonstrate that our framework outperforms a variety of strong baselines. Moreover, our analytical finds highlight the effectiveness of IPR in augmenting action efficiency and its applicability to diverse models.
Anthology ID:
2024.emnlp-main.93
Volume:
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing
Month:
November
Year:
2024
Address:
Miami, Florida, USA
Editors:
Yaser Al-Onaizan, Mohit Bansal, Yun-Nung Chen
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
1556–1572
Language:
URL:
https://aclanthology.org/2024.emnlp-main.93
DOI:
Bibkey:
Cite (ACL):
Weimin Xiong, Yifan Song, Xiutian Zhao, Wenhao Wu, Xun Wang, Ke Wang, Cheng Li, Wei Peng, and Sujian Li. 2024. Watch Every Step! LLM Agent Learning via Iterative Step-level Process Refinement. In Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing, pages 1556–1572, Miami, Florida, USA. Association for Computational Linguistics.
Cite (Informal):
Watch Every Step! LLM Agent Learning via Iterative Step-level Process Refinement (Xiong et al., EMNLP 2024)
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PDF:
https://aclanthology.org/2024.emnlp-main.93.pdf