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Agentic Reinforcement Learning with Observation-Calibrated Self-Distillation

Source

arXiv

arxiv.org/abs/2608.04788v1

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Plain-Language Brief

Researchers propose a new method called Observation-Calibrated Self-Distillation (OCSD) to train large language models in reinforcement learning. OCSD addresses a confounding issue in previous methods by comparing two replay views, Full and Observation-Ablated, to derive an observation residual that reduces the impact of score changes shared by the replay scaffold. This residual is used to adjust token-level updates at high-uncertainty steps while preserving the overall update direction. The method outperforms strong baselines in various tasks and aligns better with local environment feedback.

What the Document Says

  • The paper presents Observation-Calibrated Self-Distillation (OCSD), a new method for training large language models using reinforcement learning.
  • OCSD addresses the issue of score changes being influenced by both privileged information and the replay scaffold, which is especially problematic when future environment observations are used as privileged information due to the extended scaffold required for reconstruction.
  • To resolve this confounding, OCSD compares two replay views: Full and Observation-Ablated, and derives an observation residual that reduces score changes shared by the replay scaffold.
  • This residual is applied to adjust token-level GRPO updates at high-uncertainty steps while preserving the trajectory-level update direction.
  • The experiments show that OCSD consistently outperforms strong baselines on ALFWorld, WebShop, and Search-QA across three Qwen3 model scales.
  • Diagnostic analyses confirm that the calibrated residual aligns better with local environment feedback.

Key Concepts Mentioned

  • Large language models
  • Reinforcement learning
  • Self-Distillation
  • On-Policy Self-Distillation (OPSD)
  • Observation-Calibrated Self-Distillation (OCSD)
  • ALFWorld
  • WebShop
  • Search-QA
  • Qwen3 model scales
  • GRPO updates
  • Trajectory-level rewards
  • Token-level supervision

Claims Made by the Document

  • OCSD addresses a confounding issue in previous methods.
  • OCSD outperforms strong baselines.
  • The calibrated residual aligns better with local environment feedback.

Evidence Used

  • Comparison of two replay views (Full and Observation-Ablated) to derive an observation residual.
  • Experiments showing improved performance of OCSD over strong baselines.
  • Diagnostic analyses confirming better alignment with local environment feedback.

Methods / Approach

UNKNOWN

Limitations Stated by the Authors

  • It is unknown if the authors mention any limitations or potential drawbacks of their proposed method.

Limitations Noted by the Agent

Agent interpretation — not from the source.

  • The agent may not be able to determine the computational resources required to implement OCSD.
  • The agent may not be able to assess the generalizability of OCSD beyond the tasks and models mentioned in the paper.

Open Questions

UNKNOWN

Notes for Future Q&A

May include interpretation. Labeled where it does.

  • It is unclear what GRPO updates refer to.
  • The paper does not specify the exact nature of the strong baselines.

Raw Abstract / Excerpt

Large language model agents are commonly trained through reinforcement learning with sparse trajectory-level rewards, which offer limited guidance on how strongly individual tokens should be updated. On-Policy Self-Distillation (OPSD) addresses this by re-scoring generated tokens under a privileged replay view to obtain dense, token-level supervision. However, we identify a confounding issue: the resulting support may reflect both the privileged information contained in the replay view and score shifts induced by the replay scaffold, making it difficult to attribute the support specifically to that information. This issue is especially pronounced when future environment observations serve as privileged information, since replaying them requires reconstructing an extended scaffold that itself perturbs token scores. To resolve this confounding, we propose Observation-Calibrated Self-Distillation (OCSD), which contrasts two structurally matched replay views, Full and Observation-Ablated, differing only in whether the actual future observation is present, to derive an observation residual that discounts score changes shared by the replay scaffold. OCSD then applies this residual to modulate token-level GRPO updates at high-uncertainty steps, while preserving the trajectory-level update direction. Experiments on ALFWorld, WebShop, and Search-QA across three Qwen3 model scales show that OCSD consistently outperforms strong baselines. Diagnostic analyses further confirm that the calibrated residual aligns better with local environment feedback. Our code is publicly available at https://github.com/yiy1x/OCSD.