From Imitation to Reasoning: Sample-Efficient LLM Agents for Knowledge Graph Completion

Chenjun Zheng, Zhigang Wang, Wenjia Zhang, Zhe Wang, Xiaolin Yang


Abstract
While large language models (LLMs) have been introduced to knowledge graph completion (KGC) to improve multi-hop reasoning, most existing approaches still rely on embedding models for candidate pruning, which limits their structured reasoning capability. In contrast, fully path-based reasoning better reflects the nature of graph inference but suffers from extremely low sample efficiency. We propose AdaG-Reason, a path-based LLM-KGC framework. We formulate reasoning data synthesis as a non-stationary multi-armed bandit problem and introduce Active Reasoning Distillation to select informative trajectories by jointly considering distribution alignment, relation difficulty, and uncertainty. We further extend this bandit-based sampling principle to the reinforcement learning phase, adaptively allocating rollout queries by per-relation difficulty. For training, we propose Implicit Reasoning Distillation optimized via Step-wise Group Relative Policy Optimization (GRPO), enabling direct and stable learning of pure graph navigation policies without value function estimation. Experiments on YAGO3-10 and NELL-995 show that AdaG-Reason achieves competitive MRR and state-of-the-art Hits@1 on YAGO3-10, demonstrating the effectiveness of active data selection and pure policy learning for path-based LLM-KGC.
Anthology ID:
2026.akbc-1.26
Volume:
Proceedings of the 11th Workshop on Automated Knowledge Base Construction (AKBC 2026)
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Jan-Christoph Kalo, Ndapa Nakashole, Simon Razniewski, Fabian M. Suchanek, Andreas Vlachos, Andrew McCallum
Venues:
AKBC | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
379–392
Language:
URL:
https://aclanthology.org/2026.akbc-1.26/
DOI:
Bibkey:
Cite (ACL):
Chenjun Zheng, Zhigang Wang, Wenjia Zhang, Zhe Wang, and Xiaolin Yang. 2026. From Imitation to Reasoning: Sample-Efficient LLM Agents for Knowledge Graph Completion. In Proceedings of the 11th Workshop on Automated Knowledge Base Construction (AKBC 2026), pages 379–392, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
From Imitation to Reasoning: Sample-Efficient LLM Agents for Knowledge Graph Completion (Zheng et al., AKBC 2026)
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PDF:
https://aclanthology.org/2026.akbc-1.26.pdf