arXiv AI By Sami Nur Islam, Johan Obando-Ceron, Doina Precup, Aaron Courville, Pablo Samuel Castro

Freeze, Don't Clone: Fine-Tuning with Expressive Policies Without Retaining Offline Data

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The paper investigates fine‑tuning reinforcement learning agents when offline data cannot be retained. It shows that continuing online behavioral cloning after the offline dataset disappears erodes the pretrained policy, leading to representational collapse and loss of action diversity. By freezing the expressive prior and stopping online behavioral fitting, the authors achieve better performance across several algorithms on seven OGBench domains.

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