PEARL: Perturbation Efficient Alignment Group Relative Reinforcement Learning

Yue Huang, ChenZhuo Zhao, Zhi Yang, Pu Zhao, Fangkai Yang, Lu Wang, Mengqiao Liu, Qingwei Lin, Saravan Rajmohan, Dongmei Zhang


Abstract
Reinforcement learning with verifiable rewards (RLVR) has become a widely used approach for improving the mathematical reasoning ability of large language models (LLMs). However, recent studies show that LLMs may solve a math problem in its original form but fail when the same problem is reworded without changing its meaning. This suggests that the model has not fully acquired the underlying reasoning ability and instead relies on the surface form of the problem. In this paper, we propose PEARL, an RLVR framework that uses different versions of the same math problem as structured training signals. PEARL first groups each original problem with its checked variants to build semantic perturbation clusters, and then uses partially solved clusters as the active RL training set. PEARL further performs cluster-level RL optimization by comparing model outputs across different versions of the same mathematical problem. Experiments on mathematical reasoning benchmarks show that PEARL achieves strong results against competitive RLVR baselines while using a small active training set. These results suggest that semantically equivalent variants can serve as useful training units for improving mathematical reasoning in LLMs.
Anthology ID:
2026.findings-emnlp.1705
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
36452–36474
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URL:
https://aclanthology.org/2026.findings-emnlp.1705/
DOI:
Bibkey:
Cite (ACL):
Yue Huang, ChenZhuo Zhao, Zhi Yang, Pu Zhao, Fangkai Yang, Lu Wang, Mengqiao Liu, Qingwei Lin, Saravan Rajmohan, and Dongmei Zhang. 2026. PEARL: Perturbation Efficient Alignment Group Relative Reinforcement Learning. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 36452–36474, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
PEARL: Perturbation Efficient Alignment Group Relative Reinforcement Learning (Huang et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.1705.pdf