Group-Aware Adaptive Retrieval for Evidence Navigation

June Park, Jun Kwon, Jonghyo Kim, Jongwuk Lee


Abstract
Reasoning-intensive retrieval addresses queries whose relevance cannot be identified by surface-level matching, thereby requiring multi-step reasoning. Because relevant documents rarely appear in the initial candidate set, retrieval systems suffer from the bounded recall problem. Existing methods iteratively expand a candidate pool at the document level over a corpus graph, examining each neighbor in isolation and drifting toward a narrow region of the corpus. To address this problem, we propose Group-Aware Adaptive Retrieval for Evidence Navigation (GAREN), which explores the corpus graph through group-level expansion. GAREN organizes documents into semantically coherent and distinguishable groups based on their connections in the corpus graph. The information in each group indicates what can be accessed by expanding through it, providing guidance beyond individual document-level signals. At each iteration, GAREN uses a group-level navigator to identify promising expansion directions, retrieves documents from the selected groups, and applies a document-level reranker to evaluate the updated candidate set. Extensive experiments show that GAREN achieves up to 8.0% improvement over the strongest baseline on BRIGHT. The source code is available at https://github.com/KJ12124/GAREN
Anthology ID:
2026.emnlp-main.2143
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
48728–48747
Language:
URL:
https://aclanthology.org/2026.emnlp-main.2143/
DOI:
Bibkey:
Cite (ACL):
June Park, Jun Kwon, Jonghyo Kim, and Jongwuk Lee. 2026. Group-Aware Adaptive Retrieval for Evidence Navigation. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 48728–48747, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Group-Aware Adaptive Retrieval for Evidence Navigation (Park et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.2143.pdf