Expanding the Solvable Frontier: Policy-Adaptive Curriculum Learning for Reasoning RL

Guocong Li, Jinjian Zhang, Ping Wang, Siyan Guo, Yukai Sun, Hao Huang, Wei Zhou, Linjian Mo, Hongxia Xu, Jian Wu


Abstract
Existing curriculum learning methods for reasoning reinforcement learning often treat problem difficulty as a static property of the problem. We argue that difficulty is instead policy-dependent: problems beyond the current policy provide sparse learning signals, while problems already solved by greedy decoding may still yield informative stochastic trajectories during RL. We propose PAD-Curriculum, a policy-adaptive curriculum framework for GRPO that estimates the student’s evolving solvable frontier from student-generated trajectories. For currently solved problems, PAD-Curriculum ranks examples by a normalized Scorer-to-Student KL discrepancy computed against a frozen stronger scorer; unsolved problems are deferred and periodically re-evaluated as the policy improves. Experiments on GSM8K, MATH, and NuminaMath-CoT with Llama-3.1 and Qwen3 models show consistent gains over standard GRPO and curriculum/distillation baselines, with particularly strong improvements on challenging mathematical reasoning benchmarks. Analyses further show that adaptive discrepancy estimation is more effective than static scorer-based difficulty.
Anthology ID:
2026.emnlp-main.535
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
12329–12345
Language:
URL:
https://aclanthology.org/2026.emnlp-main.535/
DOI:
Bibkey:
Cite (ACL):
Guocong Li, Jinjian Zhang, Ping Wang, Siyan Guo, Yukai Sun, Hao Huang, Wei Zhou, Linjian Mo, Hongxia Xu, and Jian Wu. 2026. Expanding the Solvable Frontier: Policy-Adaptive Curriculum Learning for Reasoning RL. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 12329–12345, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Expanding the Solvable Frontier: Policy-Adaptive Curriculum Learning for Reasoning RL (Li et al., EMNLP 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.emnlp-main.535.pdf