CurES: From Gradient Analysis to Efficient Curriculum Learning for
  Reasoning LLMs
Authors: name: Yongcheng Zeng, name: Zexu Sun, name: Bokai Ji, name: Erxue Min, name: Hengyi Cai, name: Shuaiqiang Wang, name: Dawei Yin, name: Haifeng Zhang, name: Xu Chen, name: Jun Wang

Curriculum learning plays a crucial role in enhancing the training efficiency
of large language models (LLMs) on reasoning tasks. However, existing methods
often fail to adequately account for variations in prompt difficulty or rely on
simplistic filtering mechanisms to select prompt datasets within a narrow
criterion range, resulting in significant computational waste. In this work, we
approach the problem from the perspective of reinforcement learning gradient
optimization, offering a systematic and theoretical investigation into how to
improve the training efficiency of LLMs. We identify two key factors
influencing training efficiency: the selection of training prompts and the
allocation of rollout quantities across different prompts. Our theoretical
analysis reveals that the sampling distribution of prompts dictates the
convergence rate of gradient descent, while the allocation of the rollout
quantity influences the consistency and stability of overall gradient updates.
Based on these insights, we propose CurES, an efficient training method that
accelerates convergence and employs Bayesian posterior estimation to minimize
computational overhead. Experiments demonstrate that our CurES outperforms
Group Relative Policy Optimization (GRPO) by +3.30 points and
+4.82 points with 1.5B and 7B models, respectively. Additionally,
CurES exhibits faster convergence compared to baselines, including GRPO.