English

More Bang for the Buck: Process Reward Modeling with Entropy-Driven Uncertainty

Machine Learning 2026-03-10 v4 Artificial Intelligence Computation and Language

Abstract

We introduce the Entropy-Driven Uncertainty Process Reward Model (EDU-PRM), a novel entropy-driven training framework for process reward modeling that enables dynamic, uncertainty-aligned segmentation of complex reasoning steps, eliminating the need for costly manual step annotations. Unlike previous Process Reward Models (PRMs) that rely on static partitioning and human labeling, EDU-PRM automatically anchors step boundaries at tokens with high predictive entropy, effectively capturing intrinsic logical transitions and facilitating efficient exploration of diverse reasoning paths. On the ProcessBench benchmark, EDU-PRM outperforms strong public PRM baselines, such as Math-Shepherd PRM and Omega PRM, and EDU-PRM achieves comparable results with SOTA models while only using 1.5% training data. Furthermore, by leveraging our proposed EDU sampling strategy, we observe accuracy boosts from 64.7% to 67.3% for generative reasoning tasks, accompanied by a reduction of 32% in token usage. These findings underscore the potential of EDU-PRM as a scalable and annotation-efficient paradigm for process supervision in mathematical reasoning, paving the way for more efficient and robust approaches to complex mathematical problem solving.

Keywords

Cite

@article{arxiv.2503.22233,
  title  = {More Bang for the Buck: Process Reward Modeling with Entropy-Driven Uncertainty},
  author = {Lang Cao and Renhong Chen and Yingtian Zou and Chao Peng and Huacong Xu and Yuxian Wang and Wu Ning and Qian Chen and Mofan Peng and Zijie Chen and Peishuo Su and Yitong Li},
  journal= {arXiv preprint arXiv:2503.22233},
  year   = {2026}
}
R2 v1 2026-06-28T22:37:46.195Z