Mechanism

Augments GRPO's outcome reward with dense step-wise reasoning accuracy and formatting rewards (or serial early-exit rollouts truncated at intermediate reasoning checkpoints), rewarding the model for reaching correct conclusions earlier in the reasoning trace.

References

  1. Step-GRPO: Internalizing Dynamic Early Exit for Efficient Reasoning ↗

    Benteng Chen, Weida Wang, Shufei Zhang, Mingbao Lin, Min Zhang · 2026

  2. S-GRPO: Early Exit via Reinforcement Learning in Reasoning Models ↗

    Muzhi Dai, Chenxu Yang, Qingyi Si · 2025