Tailoring Memory Granularity for Multi-Hop Reasoning over Long Contexts

Peijun Qing, Xingjian Diao, Chiyu Ma, Saeed Hassanpour, Soroush Vosoughi


Abstract
Multi-hop reasoning over long contexts remains challenging, as it requires integrating relevant contexts scattered across distant sources while resisting semantic drift and noise from distracting content. While retrieval-augmented generation (RAG) has emerged as the prevailing solution, most RAG approaches encode and store context in monolithic memory representations, resulting in noisy retrieval and brittle reasoning. To overcome these limitations, we introduce TAG (Tailoring Memory Granularity), a framework that prestructures memory into diverse granularities and employs a reward-guided navigator to adaptively compose hybrid memory tailored to each query. The navigator is trained with a multi-objective Bradley–Terry loss that learns the relative utility of different memory types, enabling dynamic routing across granularities. This design allows RAG systems to balance fine-grained detail with high-level abstraction, yielding more reliable reasoning. Extensive experiments on long-context multi-hop question answering (QA) benchmarks show that TAG achieves state-of-the-art performance. With only 0.033% additional parameters, it remains lightweight, highlighting its practicality as a scalable and effective solution for enhancing language model agents in complex, real-world scenarios.
Anthology ID:
2026.findings-eacl.189
Volume:
Findings of the Association for Computational Linguistics: EACL 2026
Month:
March
Year:
2026
Address:
Rabat, Morocco
Editors:
Vera Demberg, Kentaro Inui, Lluís Marquez
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
3648–3666
Language:
URL:
https://preview.aclanthology.org/ingest-eacl/2026.findings-eacl.189/
DOI:
Bibkey:
Cite (ACL):
Peijun Qing, Xingjian Diao, Chiyu Ma, Saeed Hassanpour, and Soroush Vosoughi. 2026. Tailoring Memory Granularity for Multi-Hop Reasoning over Long Contexts. In Findings of the Association for Computational Linguistics: EACL 2026, pages 3648–3666, Rabat, Morocco. Association for Computational Linguistics.
Cite (Informal):
Tailoring Memory Granularity for Multi-Hop Reasoning over Long Contexts (Qing et al., Findings 2026)
Copy Citation:
PDF:
https://preview.aclanthology.org/ingest-eacl/2026.findings-eacl.189.pdf
Checklist:
 2026.findings-eacl.189.checklist.pdf