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Peiji Li

7 accepted papers

2026

Beyond Mode Collapse: Distribution Matching for Diverse Reasoning

ICML 2026poster

On-policy reinforcement learning methods like GRPO suffer from \emph{mode collapse}: they exhibit reduced solution diversity, concentrating probability mass on a single solution once discovered and ceasing exploration of alternative strategies. We show this stems from reverse KL minimization's mode-…

Cited by 0SourceScholar
2025

Case2Code: Scalable Synthetic Data for Code Generation

COLING 2025main

Large Language Models (LLMs) have shown outstanding breakthroughs in code generation. Recent work improves code LLMs by training on synthetic data generated by some powerful LLMs, which can be challenging to scale due to the dependence on a teacher model and high generation costs. In this paper, we…

2025

FastMCTS: A Simple Sampling Strategy for Data Synthesis

ACL 2025long

Synthetic high-quality multi-step reasoning data can significantly enhance the performance of large language models on various tasks. However, most existing methods rely on rejection sampling, which generates trajectories independently and suffers from inefficiency and imbalanced sampling across pro…

2025

Implicit Reward as the Bridge: A Unified View of SFT and DPO Connections

NeurIPS 2025poster

Post-training processes are essential phases in grounding pre-trained language models to real-world tasks, with learning from demonstrations or preference signals playing a crucial role in this adaptation. We present a unified theoretical framework bridging Supervised Fine-Tuning (SFT) and preferenc…

Cited by 0SourceScholar
2025

Mixing Expert Knowledge: Bring Human Thoughts Back To the Game of Go

NeurIPS 2025poster

Large language models (LLMs) have demonstrated exceptional performance in reasoning tasks such as mathematics and coding, matching or surpassing human capabilities. However, these impressive reasoning abilities face significant challenges in specialized domains. Taking Go as an example, although Alp…

Cited by 0SourceScholar
2025

UnitCoder: Scalable Code Synthesis from Pre-training Corpora

EMNLP 2025

Large Language Models (LLMs) have demonstrated remarkable capabilities in various tasks, yet code generation remains a major challenge. Despite the abundant sources of code data, constructing high-quality training datasets at scale poses a significant challenge. Pre-training code data typically suff

2024

F-Eval: Asssessing Fundamental Abilities with Refined Evaluation Methods

ACL 2024long

Large language models (LLMs) garner significant attention for their unprecedented performance, leading to an increasing number of researches evaluating LLMs. However, these evaluation benchmarks are limited to assessing the instruction-following capabilities, overlooking the fundamental abilities th…