PSR: Efficient Knowledge Graph Question Answering via Plan-Guided Schema-Level Reasoning

Mingyuan Li, Yucheng Li, Yuheng Bao, Yawei Sun, Gong Cheng


Abstract
Retrieval-Augmented Generation (RAG) enhances Large Language Models (LLMs) in Knowledge Graph Question Answering (KGQA) by retrieving reasoning paths from external Knowledge Graphs (KGs). However, the practicality of existing methods is often limited by their reliance on iterative retrieval, where the number of required LLM calls increases with retrieval depth, leading to expensive interaction costs. To address this, we propose Plan-guided Schema-level Reasoning (PSR), a training-free and efficient RAG framework for KGQA that requires only three LLM calls. First, PSR generates a retrieval plan from the input question (the first LLM call). It then performs Plan-Regularized Monte Carlo Tree Search to extract a compact set of schema-level paths from the KG, which are subsequently filtered by the LLM (the second LLM call). Finally, PSR grounds the chosen schema-level paths into instance-level reasoning paths to augment the LLM’s answer generation (the third LLM call). Experimental results on three datasets demonstrate the high efficiency and competitive accuracy of PSR.
Anthology ID:
2026.findings-emnlp.1091
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
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SIGDAT
Publisher:
Association for Computational Linguistics
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Pages:
23104–23125
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URL:
https://aclanthology.org/2026.findings-emnlp.1091/
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Cite (ACL):
Mingyuan Li, Yucheng Li, Yuheng Bao, Yawei Sun, and Gong Cheng. 2026. PSR: Efficient Knowledge Graph Question Answering via Plan-Guided Schema-Level Reasoning. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 23104–23125, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
PSR: Efficient Knowledge Graph Question Answering via Plan-Guided Schema-Level Reasoning (Li et al., Findings 2026)
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https://aclanthology.org/2026.findings-emnlp.1091.pdf