titleSG-OPD: Sign-Gated On-Policy Distillation via Sign-Consistency Gating and Phased Teacher Sampling
authorsHaoran Xu, Hongyu Wang, Yifei Gao, Jiaze Li, Xiaofeng Zhang, Xiaosong Yuan
date2026-06-08
venuearXiv (preprint, not peer reviewed)
idarXiv:2606.09304
upvotes1 (Hugging Face Daily Papers, 2026-11-01)
linksabs pdf hf
abstractOn-policy distillation (OPD) trains a student on its own trajectories with dense per-token supervision from a stronger teacher, and often outperforms off-policy distillation and standard reinforcement learning. However, we find that its effectiveness implicitly relies on two assumptions that frequently break in practice: trajectory-level alignment between the student and the teacher, and uniform token-level reliability of the teacher's preferences. We therefore propose Sign-Gated On-Policy Distillation (SG-OPD), which uses a binary verifier as a trust signal for the teacher at two complementary granularities: phased teacher sampling mixes in verifier-endorsed teacher rollouts at cold-start, and a sign-consistency gate extrapolates the distillation update on tokens where the teacher agrees with the verifier-correct direction and interpolates it where it disagrees. Experiments on competition-level mathematical reasoning benchmarks show that SG-OPD consistently outperforms standard OPD, with average gains of 1.98 and 7.50 at the per-sample and per-question levels, respectively.

cite

@misc{xu2026sg,
  title={SG-OPD: Sign-Gated On-Policy Distillation via Sign-Consistency Gating and Phased Teacher Sampling},
  author={Haoran Xu and Hongyu Wang and Yifei Gao and Jiaze Li and Xiaofeng Zhang and Xiaosong Yuan},
  year={2026},
  eprint={2606.09304},
  archivePrefix={arXiv},
  url={https://arxiv.org/abs/2606.09304}
}