titleToken-Level Off-Policy Learning for Faithful Generation Under Distribution Shift
authorsZitong Huang, Gustavo Lucas Carvalho, Deqing Fu, Robin Jia
date2026-07-20
venuearXiv (preprint, not peer reviewed)
idarXiv:2607.17524
affiliationUniversity of Southern California
upvotes6 (Hugging Face Daily Papers, 2026-11-01)
linksabs pdf hf
abstractWe propose Token-Level Off-Policy Labeling (TOPL), an off-policy training paradigm that reframes post-training as a token-level correctness prediction task. Our key intuition is that by training the model to distinguish good and bad tokens in a response, we naturally guide the model towards generating good tokens, while avoiding the pitfalls that come with directly training the model to generate off-policy tokens. Experiments on document summarization tasks show that TOPL achieves strong out-of-distribution generalization across 11 datasets against a diverse set of sequence-level and token-level baselines. We further demonstrate that TOPL transfers effectively to machine translation, suggesting that its benefits generalize across different faithful generation tasks. Through ablation studies, we confirm that our token-level learning signal is critical to good performance; sequence-level analogues do not confer similar benefits. Finally, we show that TOPL induces interpretable model updates: the LoRA adapters learned through TOPL function as linear classification heads and steering vectors.

cite

@misc{huang2026token,
  title={Token-Level Off-Policy Learning for Faithful Generation Under Distribution Shift},
  author={Zitong Huang and Gustavo Lucas Carvalho and Deqing Fu and Robin Jia},
  year={2026},
  eprint={2607.17524},
  archivePrefix={arXiv},
  url={https://arxiv.org/abs/2607.17524}
}