PSPO*: An Effective Process-supervised Policy Optimization for Reasoning Alignment

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Li, Jiawei, Liang, Xinyue, Zhang, Junlong, Yang, Yizhe, Feng, Chong, Gao, Yang
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866916736360513536
author Li, Jiawei
Liang, Xinyue
Zhang, Junlong
Yang, Yizhe
Feng, Chong
Gao, Yang
author_facet Li, Jiawei
Liang, Xinyue
Zhang, Junlong
Yang, Yizhe
Feng, Chong
Gao, Yang
contents Process supervision enhances the performance of large language models in reasoning tasks by providing feedback at each step of chain-of-thought reasoning. However, due to the lack of effective process supervision methods, even advanced large language models are prone to logical errors and redundant reasoning. We claim that the effectiveness of process supervision significantly depends on both the accuracy and the length of reasoning chains. Moreover, we identify that these factors exhibit a nonlinear relationship with the overall reward score of the reasoning process. Inspired by these insights, we propose a novel process supervision paradigm, PSPO*, which systematically outlines the workflow from reward model training to policy optimization, and highlights the importance of nonlinear rewards in process supervision. Based on PSPO*, we develop the PSPO-WRS, which considers the number of reasoning steps in determining reward scores and utilizes an adjusted Weibull distribution for nonlinear reward shaping. Experimental results on six mathematical reasoning datasets demonstrate that PSPO-WRS consistently outperforms current mainstream models.
format Preprint
id arxiv_https___arxiv_org_abs_2411_11681
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle PSPO*: An Effective Process-supervised Policy Optimization for Reasoning Alignment
Li, Jiawei
Liang, Xinyue
Zhang, Junlong
Yang, Yizhe
Feng, Chong
Gao, Yang
Artificial Intelligence
Machine Learning
Process supervision enhances the performance of large language models in reasoning tasks by providing feedback at each step of chain-of-thought reasoning. However, due to the lack of effective process supervision methods, even advanced large language models are prone to logical errors and redundant reasoning. We claim that the effectiveness of process supervision significantly depends on both the accuracy and the length of reasoning chains. Moreover, we identify that these factors exhibit a nonlinear relationship with the overall reward score of the reasoning process. Inspired by these insights, we propose a novel process supervision paradigm, PSPO*, which systematically outlines the workflow from reward model training to policy optimization, and highlights the importance of nonlinear rewards in process supervision. Based on PSPO*, we develop the PSPO-WRS, which considers the number of reasoning steps in determining reward scores and utilizes an adjusted Weibull distribution for nonlinear reward shaping. Experimental results on six mathematical reasoning datasets demonstrate that PSPO-WRS consistently outperforms current mainstream models.
title PSPO*: An Effective Process-supervised Policy Optimization for Reasoning Alignment
topic Artificial Intelligence
Machine Learning
url https://arxiv.org/abs/2411.11681