Offline RL by Reward-Weighted Fine-Tuning for Conversation Optimization

Subhojyoti Mukherjee; Viet Dac Lai; Raghavendra Addanki; Ryan Rossi; Seunghyun Yoon; Trung Bui; Anup Rao; Jayakumar Subramanian; Branislav Kveton

arXiv · 2506.06964

Offline RL by Reward-Weighted Fine-Tuning for Conversation Optimization

Subhojyoti Mukherjee·Viet Dac Lai·Raghavendra Addanki·Ryan Rossi·Seunghyun Yoon·Trung Bui·Anup Rao·Jayakumar Subramanian·Branislav Kveton

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Abstract

Offline reinforcement learning (RL) is a variant of RL where the policy is learned from a previously collected dataset of trajectories and rewards. In our work, we propose a practical approach to offline RL with large language models (LLMs). We recast the problem as reward-weighted fine-tuning, which can be solved using similar techniques to supervised fine-tuning (SFT). To showcase the value of our approach, we apply it to learning short-horizon question-answering policies of a fixed length, where the agent reasons about potential answers or asks clarifying questions. Our work stands in a stark contrast to state-of-the-art methods in this domain, based on SFT and direct preference optimization, which have additional hyper-parameters and do not directly optimize for rewards. We compare to them empirically, and report major gains in both optimized rewards and language quality.

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BibTeX RIS

Subhojyoti Mukherjee, Viet Dac Lai, Raghavendra Addanki, Ryan Rossi, Seunghyun Yoon, Trung Bui, Anup Rao, Jayakumar Subramanian, Branislav Kveton. 2026-02-16. Offline RL by Reward-Weighted Fine-Tuning for Conversation Optimization. https://arxiv.org/abs/2506.06964

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