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Mengjie Ren

4 accepted papers

2026

Tackling Length Inflation Without Trade-offs: Group Relative Reward Rescaling for Reinforcement Learning

ICML 2026poster

Reinforcement learning significantly enhances LLM capabilities but suffers from a critical issue: length inflation, where models adopt verbosity or inefficient reasoning to maximize rewards. Prior approaches struggle to address this challenge in a general and lossless manner, primarily because addit…

Cited by 0SourceScholar
2025

The Rise and Down of Babel Tower: Investigating the Evolution Process of Multilingual Code Large Language Model

ICLR 2025poster

Large language models (LLMs) have shown significant multilingual capabilities. However, the mechanisms underlying the development of these capabilities during pre-training are not well understood. In this paper, we use code LLMs as an experimental platform to explore the evolution of multilingual ca…

Cited by 1SourcePDFScholar
2024

Learning or Self-aligning? Rethinking Instruction Fine-tuning

ACL 2024long

Instruction Fine-tuning (IFT) is a crucial phase in building large language models (LLMs). Previous works mainly focus on the IFT’s role in the transfer of behavioral norms and the learning of additional world knowledge. However, the understanding of the underlying mechanisms of IFT remains signific…

2024

StructEval: Deepen and Broaden Large Language Model Assessment via Structured Evaluation

ACL 2024findings

Evaluation is the baton for the development of large language models. Current evaluations typically employ a single-item assessment paradigm for each atomic test objective, which struggle to discern whether a model genuinely possesses the required capabilities or merely memorizes/guesses the answers…