Preference-Based Self-Distillation: Beyond KL Matching via Reward Regularization
- URL: http://arxiv.org/abs/2605.05040v1
- Date: Wed, 06 May 2026 15:31:50 GMT
- Title: Preference-Based Self-Distillation: Beyond KL Matching via Reward Regularization
- Abstract summary: Existing self-distillation methods largely reduce learning to KL matching toward the context-augmented teacher model.<n>We propose textbfPreference-textbfBased textbfSelf-textbfDistillation (textbfPBSD), which revisits on-policy self-distillation through a reward-regularized perspective.
- Score: 18.027254451537342
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: On-policy distillation is an efficient alternative to reinforcement learning, offering dense token-level training signals. However, its reliance on a stronger external teacher has driven recent work on on-policy self-distillation, where the same model serves as both teacher and student under different prompt contexts. Yet, existing self-distillation methods largely reduce learning to KL matching toward the context-augmented teacher model. This approach often suffers from training instability and can degrade reasoning performance over time. Moreover, self-distillation from the same model with prompt augmentation lacks the exploratory diversity provided by a genuine external teacher. To address these limitations, we move beyond fixed-teacher KL matching and propose \textbf{P}reference-\textbf{B}ased \textbf{S}elf-\textbf{D}istillation (\textbf{PBSD}), which revisits on-policy self-distillation through a reward-regularized perspective. Instead of directly matching the teacher distribution, we derive a reward-regularized objective whose analytic optimum is a reward-reweighted teacher distribution, yielding a target policy provably superior to the original teacher under this objective. Practically, PBSD optimizes preference gaps between teacher and student samples while maintaining on-policy student sampling. We support this framework with a statistical analysis of the induced preference-learning problem, formally establishing when on policy self-distillation is preferable to learning from an external teacher in our setting. Experiments on mathematical reasoning and tool-use benchmarks across multiple model scales demonstrate that PBSD consistently achieves the strongest average performance among comparable baselines, showing improved training stability over prior self-distillation baselines while preserving token efficiency.
Related papers
- Self-OPD: On-Policy Distillation for Flow Matching Models without Teacher [36.07614733558147]
We introduce textbfSelf-OPD, a teacher-free OPD framework for flow matching models.<n>Self-OPD branches the deterministic next-state prediction into $K$ SDE candidates, rolls them out with the ODE sampler, and compares their rewards against a deterministic self-reference baseline.<n>Experiments on single and mixed reward benchmarks show that Self-OPD outperforms prior RL and OPD methods without task-specific teachers.
arXiv Detail & Related papers (2026-08-27T09:34:23Z) - dOPSD: On-Policy Self-Distillation for Diffusion Language Models [52.60302464420127]
Diffusion large language models generate text by iteratively denoising a masked sequence.<n>Supervised fine-tuning is off-policy and suffers from exposure bias, while reinforcement learning gives only sparse, sequence-level rewards.<n>On-policy self-distillation (OPSD) offers a promising alternative, using one model as both student and teacher.
arXiv Detail & Related papers (2026-07-05T17:47:29Z) - On-Policy Self-Distillation with Sampled Demonstrations Reduces Output Diversity [5.35852583397955]
On-policy self-distillation achieves strong pass@1 accuracy by using a single model as both teacher and student.<n>We show that this could come at a hidden cost: rollout diversity decreases and pass@k curves flatten.
arXiv Detail & Related papers (2026-06-24T17:59:02Z) - Prefix Teach, Suffix Fade: Local Teachability Collapse in Strong-to-Weak On-Policy Distillation [49.117085054884676]
On-policy distillation trains a student model on its own rollouts using dense feedback from a stronger teacher.<n>We operationalize this principle through a trajectory-specific release rule.<n> Experimental results across strong-to-weak distillation tasks indicate that this release rule consistently outperforms standard full-trajectory OPD.
arXiv Detail & Related papers (2026-05-13T15:05:30Z) - Teacher-Guided Policy Optimization for LLM Distillation [90.49982387646861]
Teacher-Guided Policy Optimization (TGPO) is an on-policy algorithm that incorporates dense directional guidance by leveraging teacher predictions conditioned on the student's rollout.<n>Experiments on complex reasoning benchmarks demonstrate that TGPO significantly outperforms standard baselines and is robust to different teachers.
arXiv Detail & Related papers (2026-05-13T09:20:03Z) - OGLS-SD: On-Policy Self-Distillation with Outcome-Guided Logit Steering for LLM Reasoning [19.98950359294245]
We study on-policy self-distillation (OPSD), where a language model improves its reasoning ability by distilling privileged teacher distributions along its own on-policy trajectories.<n>Despite the performance gains of OPSD, we identify a common but often overlooked mismatch between teacher and student responses.
arXiv Detail & Related papers (2026-05-12T17:00:53Z) - PAINT: Partial-Solution Adaptive Interpolated Training for Self-Distilled Reasoners [9.324642081509756]
Large language model (LLM) reasoning requires supervision that is both aligned with the model's own test-time states and informative at the token level.<n>Recent privileged on-policy self-distillation explores a middle ground by scoring student rollouts with the same model under verified solution context.<n>We propose PAINT, which masks the verified solution according to rollout-reference overlap and applies a small energy-space on a sparse set of entropy-mismatch token positions.
arXiv Detail & Related papers (2026-04-29T11:56:07Z) - Self-Distilled RLVR [57.37526213765131]
We show that learning signals solely derived from the privileged teacher result in severe information leakage and unstable long-term training.<n>We propose textbfRLSD (textbfRLVR with textbfSelf-textbfDistillation)<n>This enables RLSD to simultaneously harness the strengths of both RLVR and OPSD, achieving a higher convergence ceiling and superior training stability.
arXiv Detail & Related papers (2026-04-03T15:50:07Z) - Hindsight-Anchored Policy Optimization: Turning Failure into Feedback in Sparse Reward Settings [7.554296968064274]
We present Hindsight-Anchored Policy optimization (HAPO) for Reinforcement Learning with Verifiable Rewards (RLVR)<n>HAPO employs a hindsight mechanism that selectively anchors optimization to teacher demonstrations during failure.<n>We show that HAPO achieves textitasymptotic consistency: by naturally annealing the teacher signal as the policy improves, HAPO recovers the unbiased on-policy gradient.
arXiv Detail & Related papers (2026-03-11T21:33:41Z) - Scaling Reasoning Efficiently via Relaxed On-Policy Distillation [49.39199261602195]
REOPOLD (Relaxed On-Policy Distillation) is a framework that stabilizes optimization by relaxing the strict imitation constraints of standard on-policy distillation.<n>Specifically, REOPOLD selectively and leverages rewards from the teacher through mixture-based reward clipping, entropy-based token-level dynamic sampling, and a unified exploration-to-refinement training strategy.
arXiv Detail & Related papers (2026-03-11T16:26:52Z) - Reinforcement-aware Knowledge Distillation for LLM Reasoning [63.53679456364683]
Reinforcement learning (RL) post-training has recently driven gains in long chain-of-thought reasoning large language models (LLMs)<n>Most existing knowledge distillation methods are designed for supervised fine-tuning (SFT), relying on fixed teacher traces or teacher-student Kullback-Leibler (KL) divergence-based regularization.<n>We propose RL-aware distillation (RLAD), which performs selective imitation during RL -- guiding the student toward the teacher only when it improves the current policy update.
arXiv Detail & Related papers (2026-02-26T00:20:39Z) - Learning beyond Teacher: Generalized On-Policy Distillation with Reward Extrapolation [57.524909883706556]
On-policy distillation (OPD) has demonstrated strong empirical gains in improving student performance.<n>This work introduces a flexible reference model and a reward scaling factor that controls the relative weight of the reward term against the KL regularization.<n>In particular, in the setting where we merge the knowledge from different domain experts, obtained by applying domain-specific RL to the same student model, ExOPD enables the student to even surpass the teacher's performance boundary.
arXiv Detail & Related papers (2026-02-12T16:14:29Z) - Self-Distilled Reasoner: On-Policy Self-Distillation for Large Language Models [44.041109669153506]
On-Policy Self-Distillation (OPSD) is a framework where a single model acts as both teacher and student by conditioning on different contexts.<n>We demonstrate the efficacy of our method on multiple mathematical reasoning benchmarks.
arXiv Detail & Related papers (2026-01-26T17:56:50Z) - Stable On-Policy Distillation through Adaptive Target Reformulation [7.361248172930405]
Veto is an objective-level reformulation that constructs a geometric bridge in the logit space.<n>Veto consistently outperforms supervised fine-tuning and existing on-policy baselines.
arXiv Detail & Related papers (2026-01-12T02:57:39Z) - Learning a Diffusion Model Policy from Rewards via Q-Score Matching [93.0191910132874]
We present a theoretical framework linking the structure of diffusion model policies to a learned Q-function.<n>We propose a new policy update method from this theory, which we denote Q-score matching.
arXiv Detail & Related papers (2023-12-18T23:31:01Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.