titleOn-Policy Delta Distillation for Multilingual Math Reasoning
authorsByeongho Heo, Jaehui Hwang, Sangdoo Yun, Dongyoon Han
date2026-08-06
venuearXiv (preprint, not peer reviewed)
idarXiv:2608.05802
affiliationNAVER AI Lab
upvotes10 (Hugging Face Daily Papers, 2026-11-01)
linksabs pdf hf
abstractOn-Policy Distillation (OPD) is emerging as a promising alternative to reinforcement learning for LLM post-training, yet its effectiveness in multilingual settings remains underexplored. We study OPD and its advanced variant, On-Policy Delta Distillation (OPD^2), for mathematical reasoning in English, Korean, and Japanese. OPD^2 improves OPD by using the probability gap between a post-trained teacher and its base model as the learning signal. Experiments with Qwen3 show that OPD^2 consistently outperforms the original OPD, with particularly strong improvements in Korean and Japanese, and generally narrows the English-Korean performance gap. We further find that English-only OPD can also increase performance for Korean and Japanese, but often shifts the responses toward English, highlighting the importance of multilingual data to preserving target-language responses.

cite

@misc{heo2026policy,
  title={On-Policy Delta Distillation for Multilingual Math Reasoning},
  author={Byeongho Heo and Jaehui Hwang and Sangdoo Yun and Dongyoon Han},
  year={2026},
  eprint={2608.05802},
  archivePrefix={arXiv},
  url={https://arxiv.org/abs/2608.05802}
}