arXiv:2502.07154cs.LGcs.AI2025-02NeurIPS被引 33

训练时限制模型自信度,能显著提升数学推理的测试阶段表现。

Rethinking Fine-Tuning when Scaling Test-Time Compute: Limiting Confidence Improves Mathematical Reasoning

  • 用受限自信的损失函数替代交叉熵,避免过自信
  • 在MATH和MiniF2F上,测试时搜索更多样本仍能提升准确率
  • 适合关注推理能力优化的模型开发者

大型语言模型在数学推理等复杂任务上表现出色,关键在于测试阶段可扩展的计算资源。本文聚焦于pass@N这一简单策略:通过N次独立采样寻找正确答案。研究发现,使用交叉熵(CE)训练会导致模型过自信,反而使pass@N准确率随训练时间延长而下降。我们揭示了这种偏差源于CE带来的过度自信,并通过实验验证其阻碍了测试阶段计算扩展的效果。为此,提出一种新的训练损失函数,主动限制模型置信度,与pass@N目标更对齐。该方法在MATH和MiniF2F基准上,无论是在解答数学题还是在不同结构的证明树中搜索定理时,均显著提升了性能。本工作强调应协同设计训练阶段与测试阶段的推理策略。

原文摘要 · Abstract (English)

Recent progress in large language models (LLMs) highlights the power of scaling test-time compute to achieve strong performance on complex tasks, such as mathematical reasoning and code generation. This raises a critical question: how should model training be modified to optimize performance under a subsequent test-time compute strategy and budget? To explore this, we focus on pass@N, a simple test-time strategy that searches for a correct answer in $N$ independent samples. We show, surprisingly, that training with cross-entropy (CE) loss can be ${\it misaligned}$ with pass@N in that pass@N accuracy ${\it decreases}$ with longer training. We explain the origins of this misalignment in terms of model overconfidence induced by CE, and experimentally verify our prediction of overconfidence as an impediment to scaling test-time compute via pass@N. Furthermore we suggest a principled, modified training loss that is better aligned to pass@N by limiting model confidence and rescuing pass@N test performance. Our algorithm demonstrates improved mathematical reasoning on MATH and MiniF2F benchmarks under several scenarios: (1) providing answers to math questions; and (2) proving theorems by searching over proof trees of varying shapes. Overall our work underscores the importance of co-designing two traditionally separate phases of LLM development: training-time protocols and test-time search and reasoning strategies.

数学推理测试阶段计算模型自信训练优化

Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。