On the Design of KL-Regularized Policy Gradient Algorithms for LLM Reasoning
Yifan Zhang, Yifeng Liu, Huizhuo Yuan, Yang Yuan, Quanquan Gu, Andrew C Yao
2025-05-26
Summary
This paper talks about a new way to train large language models to reason better by using a special technique that helps the model learn more steadily and effectively during training.
What's the problem?
The problem is that when AI models are trained to reason and make decisions, especially using reinforcement learning, the training process can be unstable and the models might not get as good at reasoning as they could.
What's the solution?
The researchers introduced a method called KL-regularized policy gradient, which uses a mathematical tool called KL divergence to guide the learning process. This helps the model stay on track and learn to reason more reliably, leading to better and more stable performance.
Why it matters?
This is important because it means language models can become much better at logical thinking and decision-making, which is useful for tasks like problem-solving, planning, and helping people with complex questions.
Abstract
A regularized policy gradient framework is introduced to explore KL divergence formulations for enhancing the reasoning capabilities of LLMs in online reinforcement learning, demonstrating improved training stability and performance.