Promoting Efficient Reasoning with Verifiable Stepwise Reward

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Yue, Chuhuai, Dong, Chengqi, Gao, Yinan, He, Hang, Chai, Jiajun, Yin, Guojun, Lin, Wei
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909738354081792
author Yue, Chuhuai
Dong, Chengqi
Gao, Yinan
He, Hang
Chai, Jiajun
Yin, Guojun
Lin, Wei
author_facet Yue, Chuhuai
Dong, Chengqi
Gao, Yinan
He, Hang
Chai, Jiajun
Yin, Guojun
Lin, Wei
contents Large reasoning models (LRMs) have recently achieved significant progress in complex reasoning tasks, aided by reinforcement learning with verifiable rewards. However, LRMs often suffer from overthinking, expending excessive computation on simple problems and reducing efficiency. Existing efficient reasoning methods typically require accurate task assessment to preset token budgets or select reasoning modes, which limits their flexibility and reliability. In this work, we revisit the essence of overthinking and identify that encouraging effective steps while penalizing ineffective ones is key to its solution. To this end, we propose a novel rule-based verifiable stepwise reward mechanism (VSRM), which assigns rewards based on the performance of intermediate states in the reasoning trajectory. This approach is intuitive and naturally fits the step-by-step nature of reasoning tasks. We conduct extensive experiments on standard mathematical reasoning benchmarks, including AIME24 and AIME25, by integrating VSRM with PPO and Reinforce++. Results show that our method achieves substantial output length reduction while maintaining original reasoning performance, striking an optimal balance between efficiency and accuracy. Further analysis of overthinking frequency and pass@k score before and after training demonstrates that our approach in deed effectively suppresses ineffective steps and encourages effective reasoning, fundamentally alleviating the overthinking problem. All code will be released upon acceptance.
format Preprint
id arxiv_https___arxiv_org_abs_2508_10293
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Promoting Efficient Reasoning with Verifiable Stepwise Reward
Yue, Chuhuai
Dong, Chengqi
Gao, Yinan
He, Hang
Chai, Jiajun
Yin, Guojun
Lin, Wei
Artificial Intelligence
Large reasoning models (LRMs) have recently achieved significant progress in complex reasoning tasks, aided by reinforcement learning with verifiable rewards. However, LRMs often suffer from overthinking, expending excessive computation on simple problems and reducing efficiency. Existing efficient reasoning methods typically require accurate task assessment to preset token budgets or select reasoning modes, which limits their flexibility and reliability. In this work, we revisit the essence of overthinking and identify that encouraging effective steps while penalizing ineffective ones is key to its solution. To this end, we propose a novel rule-based verifiable stepwise reward mechanism (VSRM), which assigns rewards based on the performance of intermediate states in the reasoning trajectory. This approach is intuitive and naturally fits the step-by-step nature of reasoning tasks. We conduct extensive experiments on standard mathematical reasoning benchmarks, including AIME24 and AIME25, by integrating VSRM with PPO and Reinforce++. Results show that our method achieves substantial output length reduction while maintaining original reasoning performance, striking an optimal balance between efficiency and accuracy. Further analysis of overthinking frequency and pass@k score before and after training demonstrates that our approach in deed effectively suppresses ineffective steps and encourages effective reasoning, fundamentally alleviating the overthinking problem. All code will be released upon acceptance.
title Promoting Efficient Reasoning with Verifiable Stepwise Reward
topic Artificial Intelligence
url https://arxiv.org/abs/2508.10293