Training-Free Residual-Guided Retrieval for Multi-hop KGQA with Single-Step LLM Inference

Keito Sei, Sunil Kumar Maurya, Yohei Kobashi, Yutaka Matsuo


Abstract
Graph-based retrieval is effective for knowledge graph question answering (KGQA), but retrieving the correct reasoning path remains challenging in multi-hop settings because the retrieval objective changes as reasoning progresses. Existing methods often address this issue with repeated LLM-based planning, which improves adaptivity but increases inference cost. We present a training-free residual-guided retrieval framework that updates the retrieval signal according to the current reasoning path in embedding space. The method performs multi-hop graph retrieval without repeated hop-wise LLM calls and invokes the LLM only once for final answer generation. Experiments on WebQSP and CWQ show that our method achieves superior Hit rates with only a single LLM call. Additional comparisons with supervised graph-based KGQA methods show that the proposed method remains effective without task-specific training data. These results suggest that residual-guided retrieval is an efficient alternative for multi-hop graph-based question answering.
Anthology ID:
2026.aacl-short.29
Volume:
Proceedings of the 15th International Joint Conference on Natural Language Processing and the 5th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics (Volume 2: Short Papers)
Month:
November
Year:
2026
Address:
Hengqin, China
Editors:
Yue Zhang, Ruifeng Xu, Ayu Purwarianti, Tong Rong, Jun Suzuki
Venues:
AACL | IJCNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
430–442
Language:
URL:
https://aclanthology.org/2026.aacl-short.29/
DOI:
Bibkey:
Cite (ACL):
Keito Sei, Sunil Kumar Maurya, Yohei Kobashi, and Yutaka Matsuo. 2026. Training-Free Residual-Guided Retrieval for Multi-hop KGQA with Single-Step LLM Inference. In Proceedings of the 15th International Joint Conference on Natural Language Processing and the 5th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics (Volume 2: Short Papers), pages 430–442, Hengqin, China. Association for Computational Linguistics.
Cite (Informal):
Training-Free Residual-Guided Retrieval for Multi-hop KGQA with Single-Step LLM Inference (Sei et al., AACL-IJCNLP 2026)
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PDF:
https://aclanthology.org/2026.aacl-short.29.pdf