Curating multi-mode chain of thought for efficient math reasoning with GPT-OSS
Fewer, cleaner reasoning traces make a better student model.
Overview
We distilled math reasoning from a GPT-OSS teacher into Llama 3.2 3B. The teacher wrote solutions at low, medium and high reasoning budgets; we kept only traces with a verified final answer and a sensible length.
Distillation datasets are noisy: wrong answers with confident reasoning, and traces that ramble for pages. We bet on fewer, cleaner samples rather than more of them.
I built the curation pipeline — generating multi-budget traces from the teacher, verifying final answers, filtering by length around the median — and ran the SFT and GRPO workflows on LLaMA-Factory and MS-SWIFT.
The student trained on the shortest, low-budget traces came out best after GRPO: GSM8K 0.8006 and MATH500 0.4760 zero-shot, up from 0.7043 and 0.3960.
Compare teacher budgets
Teacher reasoning budget used to write the training traces
- GSM8K0.8006
- MATH5000.4760
Llama 3.2 3B after SFT and GRPO, zero-shot accuracy. The tick marks the same model before distillation: GSM8K 0.7043, MATH500 0.3960.
Results, Llama 3.2 3B, 0-shot
| Student | GSM8K | MATH500 |
|---|---|---|
| Before distillation | 0.7043 | 0.3960 |
| SFT on low-budget traces, then GRPO | 0.8006 | 0.4760 |
| SFT on medium-budget traces, then GRPO | 0.7771 | 0.4480 |
| SFT on high-budget traces, then GRPO | 0.7559 | 0.4740 |
Built with
Cite
@inproceedings{trinh2026multimode,
title = {Curating Multi-Mode CoT for Efficient Math Reasoning with GPT-OSS},
author = {Trinh, Hai-Au and Vu, Tue-Anh and Tran, Dai-Nhan and Huynh, Uyen Khoi-Minh and Nguyen, Anh-Khoi},
booktitle = {ICISN 2026},
year = {2026},
note = {Accepted},
url = {https://github.com/hugebenevolence/LLaMA-OSS}
}