Organizations: Beijing Advanced Innovation Center for Future Blockchain and Privacy Computing, Beihang University · School of Artificial Intelligence, Beihang University
Reinforcement learning with verifiable rewards (RLVR) has shown strong empirical gains in improving the reasoning ability of large language models (LLMs) on tasks such as mathematics and programming. However, recent studies have shown that RLVR rollouts often collapse onto a narrow set of reasoning trajectories, limiting the explored reasoning space. Motivated by findings that thinking tokens at critical steps serve as critical structural elements in LLM reasoning pathways, we propose Guided-RLVR, a novel approach that augments RLVR with a lightweight controller. The controller strategically injects semantically meaningful steering tokens into the sampling distribution, encouraging the model to approach problems from multiple reasoning perspectives and thereby expanding the exploration space. Experiments on mathematical reasoning and code generation benchmarks show that Guided-RLVR consistently outperforms existing RLVR methods while producing more diverse reasoning trajectories.
Figures & tables
Figure 1: t-SNE ( van der Maaten and Hinton 2008 ) visualization of final-layer rollout representations from vanilla RLVR and guided steering, with 32 rollouts per problem. Total variance is computed in the standardized high-dimensional representation space before projection.
Figure 2: Overview of Guided-RLVR. (a) For each prompt x , policy πθ generates G=10 rollouts: two unperturbed (greedy and stochastic) and eight guided. (b) At sentence boundaries where next-token entropy H(πθ) exceeds the dynamic threshold τt , the Logic Controller μϕ maps aggregated hidden states ∑h to a semantic action at and steering token vk . A bias δ boosts its logit zt(vk) toward probability ptarget=0.5 before sampling the next token yt from the perturbed distribution πpert . (c) Reward ri combines task correctness rtask with a bonus αf(Δℓ) , granted only to correct math rollouts where a promoted token was sampled. Here Δℓ=ℓbase−ℓcot measures the same answer’s log-perplexity reduction when conditioned on the reasoning chain; f normalizes and clips this difference, and α scales the bonus. Group mean μr , standard deviation σr , and stabilizer ϵ normalize rewards into advantages A^i shared by policy and controller updates.
Method
MATH
AIME2024
AIME2025
AMC2023
Code-R1
AVG
pass@1
pass@16
pass@1
pass@128
pass@1
pass@128
pass@1
pass@128
pass@1
pass@16
Qwen2.5-7B-Instruct
GRPO
62.1
79.4
11.20
46.67
5.99
50.00
43.23
90.36
82.0
94.8
56.58
GRPO + ENT
64.5
78.8
7.97
46.67
7.06
46.67
39.31
91.57
80.4
93.2
55.62
GRPO + REP
64.9
78.0
10.89
50.00
6.48
50.00
43.22
91.57
82.6
95.6
57.33
GRPO + Ours
65.6
80.6
12.11
53.33
5.03
53.33
42.77
92.77
82.6
96.0
58.41
Table 1: Main results across two backbones (Qwen2.5-7B-Instruct and Qwen3-4B) and two RLVR algorithms (GRPO and DAPO). All values are percentages. Ours denotes Guided-RLVR. AVG is the unweighted mean of the ten reported metrics. Within each backbone and RLVR algorithm block, the best value in each column is shown in bold; ties are also shown in bold.
Figure 3: Trajectory diversity across sampling budgets on MATH using Qwen2.5-7B-Instruct with GRPO. Solid lines denote TD and dashed lines denote ED; higher values indicate greater diversity.
Figure 4: Pass@ k scaling across all five benchmarks using Qwen3-4B with GRPO. The maximum sampling budget is k=128 for AIME2024, AIME2025, and AMC2023, and k=16 for MATH and Code-R1.
Method
MATH
AIME2024
AIME2025
AMC2023
GRPO
326.36
1224.94
935.95
818.50
GRPO + ENT
413.90
1224.84
910.15
724.80
GRPO + REP
407.15
1207.24
964.91
794.88
GRPO + Ours
338.04
1087.85
748.06
693.89
Table 2: Average generation length in tokens for the GRPO variants on four mathematical benchmarks using Qwen2.5-7B-Instruct, averaged over all completions. Lower values indicate shorter generations.
Variant
pass@1
pass@16
Vanilla GRPO
62.1
79.4
Guided-RLVR
65.6
80.6
(a) Random steering token selection
63.4
77.2
(b) Fixed steering token (“Wait”)
63.9
78.2
(c) No entropy threshold
62.1
79.2
(d) No log-perplexity reward
62.0
79.6
Table 3: Component ablation on MATH using Qwen2.5-7B-Instruct with GRPO. All values are percentages. Both pass@1 and pass@16 are estimated from 16 independent samples per problem at the selected checkpoint.
Figure 5: Effect of the log-perplexity reward coefficient α on MATH evaluation accuracy during training using Qwen2.5-7B-Instruct.
Method
GPU-h
s/step
GRPO
15.92
11.46
GRPO + ENT
14.22
10.24
GRPO + REP
16.55
11.92
GRPO + Ours
17.92
12.90
Table 4: RL-stage compute cost under the shared timing configuration. Ours denotes Guided-RLVR without supervised controller cold start.
Appendix figures & tables6 assets
Supplementary material from the paper’s appendix.
Appendix
Category
Tokens
Semantic function
Reflection
Wait
Revisit or reconsider a step
Progression
Then
Advance to the next step
Causality
Therefore , Hence
Draw a consequence
Causal Reflection
Since , Because
Justify by a prior cause
Contrast
But , However
Introduce an opposing turn
Hypothesis
If
Pose a conditional assumption
Appendix
Table 5: Steering token vocabulary T , grouped by the six semantic categories the controller predicts. Within a category, the injected token is drawn in proportion to its frequency in the cold-start DeepSeek-R1 traces.
Hyperparameter
Value
Sampling temperature (training)
1.0
Sampling temperature (evaluation)
0.7
KL penalty coefficient ( β )
0
Decoupled clipping (high)
0.28
Decoupled clipping (low)
0.2
Rollouts per prompt ( G )
10
Appendix
Table 6: Training hyperparameters shared across all methods and datasets.
Dataset
Token Length
Batch Size
Train Batch
Qwen2.5-7B-Instruct
MATH
1024
40
4
AIME2024/2025
8192
100
20
AMC2023
8192
100
20
Code-R1
8192
40
4
Qwen3-4B
Appendix
Table 7: Detailed training configuration for each backbone model and dataset.
Benchmark
# Problems
Difficulty
K
AIME2024 / 2025
30
Extremely hard
128
AMC2023
83
Hard
128
MATH
500
Moderate
16
Code-R1
500
Moderate
16
Appendix
Table 8: Sampling budget K used for pass@ K evaluation on each benchmark.
Figure 6: Controller behavior on MATH using Qwen2.5-7B-Instruct with GRPO. Panel (a) shows the cumulative proportion of each steering-token action over training steps. Panel (b) reports the number of interventions and the subsequent rollout accuracy for each token. The accuracy values are descriptive rather than causal because tokens are selected in different reasoning states and have unequal sample counts.
Figure 7: Training entropy on MATH using Qwen2.5-7B-Instruct with GRPO. Removing the entropy threshold (orange) leads to an overall increase after the initial decrease; the full Guided-RLVR configuration (blue) maintains lower entropy during later training.
School of Data Science, Fudan University · Shanghai Institute of Artificial Intelligence for Education, East China Normal University · College of Computer Science and Artificial Intelligence, Fudan University +1