arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 2602.01523cs.LGcs.AIcs.CL
收藏

一种用于大语言模型推理中可验证奖励的相对预算理论

A Relative-Budget Theory for Reinforcement Learning with Verifiable Rewards in Large Language Model Reasoning

LY Corporation(LY公司);Toyota Technological Institute at Chicago(丰田技术研究所(芝加哥));University of Tokyo(东京大学)

Akifumi Wachi, Hirota Kinoshita, Shokichi Takakura, Rei Higuchi, Taiji Suzuki

AI总结:

本文提出一种相对预算理论,通过相对预算ξ=H/E[T]解释强化学习在大语言模型推理中的样本效率差异,并通过实验证明在ξ∈[1.5,2.0]时学习效率最高。

摘要:

强化学习(RL)是提升大语言模型推理能力的主要范式,但其效果在不同任务和计算预算下存在差异。我们提出了一种相对预算理论,通过一个称为相对预算ξ:= H/ E[T]的单一量来解释这种差异,其中H是生成时间跨度(token预算),T表示在基础策略下首次正确解决方案前的token数量。我们证明ξ通过控制奖励方差和信息轨迹的可能性来决定样本效率。我们的分析揭示了三个阶段:在贫乏阶段(ξ→0),信息轨迹稀少,样本复杂度爆炸;在平衡阶段(ξ=Θ(1)),信息轨迹出现的概率非可忽略,RL达到最大样本效率;在充足阶段(ξ→∞),学习保持稳定但每次迭代的边际收益减少。我们进一步为在线RL提供有限样本保证,这些保证描述了这些阶段中的学习进展。具体而言,在理想分布假设下的案例研究中,我们显示相对预算随迭代线性增长。我们的实证结果验证了这些预测,在现实设置中,识别了一个预算ξ∈[1.5, 2.0],该预算最大化学习效率并与推理性能峰值一致。

英文摘要:

Reinforcement learning (RL) is a dominant paradigm for improving the reasoning abilities of large language models, yet its effectiveness varies across tasks and compute budgets. We propose a \emph{relative-budget} theory explaining this variation through a single quantity called relative budget $ξ:= H/\mathbb{E}[T]$, where $H$ is the generation horizon (token budget) and $T$ denotes the number of tokens until the first correct solution under a base policy. We show that $ξ$ determines sample efficiency by controlling reward variance and the likelihood of informative trajectories. Our analysis reveals three regimes: in the \emph{deficient} regime ($ξ\to 0$), informative trajectories are rare and the sample complexity explodes; in the \emph{balanced} regime ($ξ=Θ(1)$), informative trajectories occur with non-negligible probability and RL is maximally sample-efficient; and in the \emph{ample} regime ($ξ\to \infty$), learning remains stable but marginal gains per iteration diminish. We further provide finite-sample guarantees for online RL that characterize learning progress across these regimes. Specifically, in a case study under idealized distributional assumptions, we show that the relative budget grows linearly over iterations. Our empirical results confirm these predictions in realistic settings, identifying a budget $ξ\in [1.5, 2.0]$ that maximizes learning efficiency and coincides with peak reasoning performance.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑