arXiv AI By Runchu Tian, Zaid Khan, Zun Wang, Justin Chih-Yao Chen, Mohit Bansal

MiRL: Error-Targeted Reinforcement Learning for Correcting Terminal Agent Misbehaviors

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MiRL is a new reinforcement learning approach that targets specific misbehaviors of terminal agents—models that execute long‑horizon tasks in natural language by interacting with a command shell. The method first profiles a policy to identify recurring wrong steps, then trains the policy by starting rollouts at those misbehaviors and rewarding only successful, misbehavior‑free trajectories. On the Qwen3.5‑4B model, MiRL reduces repeated misbehaviors by 43–57% on unseen prefixes and outperforms or matches baseline agents on Terminal‑Bench benchmarks while using only 35% of the rollouts.

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arXiv AI
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arXiv:2608. 08570v1 Announce Type: new Abstract: Rejection sampling fine-tuning (RFT) is widely used to train code agents by generating trajectories on verifiable software engineering tasks, retaining those that pass the tests, and fine-tuning on the successful rollouts.

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Hugging Face Trending Papers
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arXiv AI
Oct 1

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By Kunlun Zhu, Xuyan Ye, Yibo Li, Cheng Qian, Beibin Li, Heng Ji
arXiv Computation and Language
Oct 21

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By Tianyi Lorena Yan, John Hewitt