Know What You Know: Metacognitive Entropy Calibration for Verifiable RL Reasoning
Abstract
Large reasoning models (LRMs) have emerged as a powerful paradigm for solving complex real-world tasks. In practice, these models are predominantly trained via Reinforcement Learning with Verifiable Rewards (RLVR), yet most existing outcome-only RLVR pipelines rely almost exclusively on a binary correctness signal and largely ignore the model's intrinsic uncertainty. We term this discrepancy the uncertainty-reward mismatch, under which high- and low-uncertainty solutions are treated equivalently, preventing the policy from "Know What You Know" and impeding the shift from optimizing for correct answers to optimizing effective reasoning paths. This limitation is especially critical in reasoning-centric tasks such as mathematics and question answering, where performance hinges on the quality of the model's internal reasoning process rather than mere memorization of final answers. To address this, we propose EGPO, a metacognitive entropy calibration framework that explicitly integrates intrinsic uncertainty into RLVR for enhancing LRMs. EGPO estimates per-sample uncertainty using a zero-overhead entropy proxy derived from token-level likelihoods and aligns it with extrinsic correctness through an asymmetric calibration mechanism that preserves correct reasoning while selectively regulating overconfident failures, thereby enabling stable and uncertainty-aware policy optimization. Moreover, EGPO recovers informative learning signals from otherwise degenerate group-based rollouts without modifying the verifier or reward definition. Extensive experiments across multiple benchmarks demonstrate that the proposed EGPO leads to substantial and consistent improvements in reasoning performance, establishing a principled path for advancing LRMs through metacognitive entropy calibration.
Figures & tables
| Model | MATH-500 | AIME24 | MMLU-STEM | Minerva | GSM8K |
|---|---|---|---|---|---|
| 1.5B Models | |||||
| Qwen2.5-Math-1.5B (Base) | 23.40 | 6.67 | 17.44 | 19.90 | 58.15 |
| Qwen2.5-Math-1.5B + GRPO ( Yu et al., 2025 ) | 67.20 (+43.80) | 13.33 (+6.66) | 20.84 (+3.40) | 32.26 (+12.36) | 71.65 (+13.50) |
| Qwen2.5-Math-1.5B + DAPO ( Yu et al., 2025 ) | 69.80 (+46.40) | 13.33 (+6.66) | 22.52 (+5.08) | 33.09 (+13.19) | 72.33 (+14.18) |
| Qwen2.5-Math-1.5B + EDGE-GRPO ( Zhang et al., 2025 ) | 72.00 (+48.60) | 16.67 (+10.00) | 23.78 (+6.34) | 33.82 (+13.92) | 74.68 (+16.53) |
| Qwen2.5-Math-1.5B + EGPO (ours) | 74.00 (+50.60) | 13.33 (+6.66) | 25.69 (+8.25) | 37.13 (+17.23) | 79.83 (+21.68) |
| Variant | Constraint on | Entirely-incorrect groups | Renorm | MATH-500 | Minerva | GSM8K | Avg. |
|---|---|---|---|---|---|---|---|
| Base | – | – | – | 23.4 | 19.90 | 58.15 | 33.82 |
| C1 (symmetric) | NSR + | none | 66.0 | 33.09 | 80.97 | 60.02 | |
| C2 (neg only) | when only | NSR + | none | 70.6 | 30.51 | 78.01 | 59.71 |
| C3 (pos only) | when only | NSR + | none | 72.6 | 33.04 | 80.59 | 62.08 |
| C4 (neg locked to 1) | asymmetric clamp | NSR with | none | 72.0 | 34.61 | 79.68 | 62.10 |
| C5 (clamp renorm) | asymmetric clamp | NSR + | after clamp | 81.05 | 35.29 | 80.29 | 65.54 |
| Backbone | TE | AE |
|---|---|---|
| DeepSeek-R1-Distill-Qwen-1.5B | 0.745 | 0.778 |
| DeepSeek-R1-Distill-Qwen-7B | 0.700 | 0.738 |
Appendix figures & tables6 assets
Supplementary material from the paper’s appendix.
Appendix
| Item | Setting |
|---|---|
| Pool size / Val size | 10,000 / 128 |
| Subset ratio | default 0.85, extended 0.15 |
| Bucket ratio | mixed 0.60, entirely_correct 0.40 (entirely_incorrect retained for robustness) |
| Min generations | |
| Length filters | prompt ; response (tokenizer-based) |
| Answer constraints | single-value GT enforced; empty GT dropped |
RL for Language Model Reasoning
Reinforcement learning for language model reasoning uses reward-driven training to improve multi-step problem solving, tool use, and reliable answers.
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