Skip to content
Preprint

EviSD: Evidence-Conditioned Self-Distillation for Search-Augmented Agents

Aug 2026 · 0 citations · 19 references
Computer Science

TL;DR

EviSD is proposed, an evidence-conditioned self-distillation framework that uses instance-level supporting evidence as privileged information for search actions and golden answers as complementary privilege for answer actions, and achieves the highest macro-average Exact Match in all evaluated settings.

Abstract

Outcome-based reinforcement learning enables search-augmented language agents to learn from verifiable final answers, but its trajectory-level credit cannot distinguish the contributions of individual actions in a multi-turn search process. We propose EviSD, an evidence-conditioned self-distillation framework that uses instance-level supporting evidence as privileged information for search actions and golden answers as complementary privilege for answer actions. During training, the student samples actions from the original context, while the same model re-scores them as a privileged teacher under an action-aligned context. EviSD converts the detached teacher--student gap into a bounded correction to the outcome-derived GRPO advantage and applies it only to generated action spans. This design localizes privileged guidance while preserving the update direction determined by the outcome reward, without an auxiliary distillation objective or any change at inference time. Across seven question-answering benchmarks and three backbones spanning model scales and generations, EviSD achieves the highest macro-average Exact Match in all evaluated settings, outperforming the strongest compared methods by 1.3--2.3 points while modulating only 6.7%--15.1% of response tokens. Code is available at https://github.com/JiananXie/EviSD.

View source

Similar papers

Jul 2026

EviBack: Search-Agent Reinforcement Learning via Evidence-Constrained Teacher Backoff

EviBack is presented, an evidence- constrained Teacher backoff that supplies auxiliary super- vision to such groups while preserving verifiable Actor re- wards, and separates evidence assessment from answer refine- ment, preventing reference answers from overriding evidence- insufficiency judgments.

Xiao Ma, Zhiquan Hu, Yi Wei et al. · 0 citations
Preprint Jul 2026

From Scoring to Acting: Outcome-Verified Comparative Self-Distillation for LLM Agents

Recent work on LLM agents is shifting from external capability elicitation to capability internalization, enabling agents to retain useful skills without retrieval at inference time. On-policy self-distillation (OPSD) offers a promising direction, but many existing methods typically supervise students by scoring actions along student-generated trajectories. Such supervision has two limitations: teacher preferences are not validated by environment outcomes, and action-level scores underuse information from student rollouts, teacher rollouts, and their behavioral relationship. We therefore advocate outcome-verified teacher supervision and comparative learning over teacher-student trajectories. Based on this view, we propose Outcome-Verified Comparative Self-Distillation (OVCSD). OVCSD organizes failed student rollouts into a prefix tree, adaptively invokes a skill-conditioned teacher from student-reached states, and retains only outcome-verified successful continuations. It then applies localized comparative learning at the first state-aligned divergence and distills the post-divergence teacher suffix to transfer completion behavior. Experiments on ALFWorld and WebShop across three model scales show that OVCSD consistently outperforms skill-free RL and existing self-distillation baselines, achieving up to 29.7 and 5.4 absolute success-rate gains over the strongest baselines on ALFWorld and WebShop, respectively, while adding less than 3% privileged interaction during training.

Xuanye Xia, J. Piao, Min Yang et al. · 0 citations
Preprint Aug 2026

Beyond Outcome Rewards: Step-Level Self-Distilled Policy Optimization for Deep Search Agents

Evidence Anchors are constructed, which are concise, step-level evidence snippets extracted from the web, as privileged information that captures key reasoning steps without revealing the entire answer path, and SSPO, which converts teacher-student disagreement into step-level advantage weights within GRPO, applied exclusively to incorrect trajectories.

Haoze Wu, Chuqiao Kuang, Tianyi Zhuang et al. · 0 citations
Preprint Aug 2026

AgentOPSD: Recursive Self-Distillation for Agentic Reinforcement Learning

This work proposes AgentOPSD, a critic-free, recursive method for turn-level credit assignment in agentic reinforcement learning that aggregates token-level teacher-student log-probability gaps into turn-level evidence and recursively updates a Bayesian belief state in log-odds space.

Zi-Han Wang, Zhengxi Lu, Zhiyuan Yao et al. · 1 citation
Jul 2026

Group-Reflective Self-Distillation for Agentic Reinforcement Learning

Group-Reflective Self-Distillation (GRSD), which derives capability-aligned and outcome-discriminative guidance from the policy's own verified rollouts, and refines turn-level credit assignment by modulating outcome-based advantages while preserving the verifier-determined learning direction.

Binbin Zheng, Zi-Jun Xie, Guan-Qun Zhao et al. · 1 citation
Preprint Aug 2026

Agentic Reinforcement Learning with Observation-Calibrated Self-Distillation

Observation-Calibrated Self-Distillation (OCSD), which contrasts two structurally matched replay views, Full and Observation-Ablated, to derive an observation residual that discounts score changes shared by the replay scaffold, and applies this residual to modulate token-level GRPO updates at high-uncertainty steps, while preserving the trajectory-level update direction.

Y. Yang, Congming Qin, Xiaodan Liu et al. · 1 citation

We use cookies to run the site and, with your consent, for analytics and to show ads. See our Cookie Policy.