PRISM: Agentic Retrieval with LLMs for Multi-Hop Question Answering

Md Mahadi Hasan Nahid, Davood Rafiei


Abstract
Retrieval plays a central role in multi-hop question answering (QA), where answering complex questions requires gathering multiple pieces of evidence. We propose PRISM, an agentic retrieval framework that leverages large language models (LLMs) in a structured loop to retrieve relevant evidence with high precision and recall. PRISM decomposes retrieval into three specialized agents: a Question Analyzer that breaks complex queries into sub-questions, a Selector that identifies the most relevant context for each sub-question (focusing on precision), and an Adder that brings in any missing evidence (focusing on recall). The iterative interaction between the Selector and Adder produces a compact yet comprehensive evidence set, avoiding both brittle error propagation and noisy context accumulation. It achieves higher retrieval accuracy while filtering out distracting content, enabling downstream QA models to surpass full-context answer accuracy while relying on significantly less irrelevant information. Experiments on four challenging multi-hop QA benchmarks, including HotpotQA, 2WikiMultiHopQA, MuSiQue, and MultiHopRAG, demonstrate that our approach consistently outperforms strong baselines.
Anthology ID:
2026.emnlp-main.1764
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:
40210–40230
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1764/
DOI:
Bibkey:
Cite (ACL):
Md Mahadi Hasan Nahid and Davood Rafiei. 2026. PRISM: Agentic Retrieval with LLMs for Multi-Hop Question Answering. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 40210–40230, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
PRISM: Agentic Retrieval with LLMs for Multi-Hop Question Answering (Nahid & Rafiei, EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1764.pdf