Inter-Passage Verification for Multi-evidence Multi-answer QA

Bingsen Chen, Shenji Wan, Xi Ye, Chen Zhao


Abstract
Multi-answer question answering (QA), where questions can have many valid answers, presents a significant challenge for existing retrieval-augmented generation-based QA systems, as these systems struggle to retrieve and then synthesize a large number of evidence passages. To tackle these challenges, we propose a new multi-answer QA framework – Retrieval-augmented Independent Reading with Inter-passage Verification (RI²VER). Our framework retrieves a large set of passages and processes each passage individually to generate an initial high-recall but noisy answer set. Then we propose a new inter-passage verification pipeline that validates every candidate answer through (1) Verification Question Generation, (2) Gathering Additional Evidence, and (3) Verification with inter-passage synthesis. Evaluations on the QAMPARI and RoMQA datasets demonstrate that our framework significantly outperforms existing baselines across various model sizes, achieving an average F1 score improvement of 11.17%. Further analysis validates that our inter-passage verification pipeline enables our framework to be particularly beneficial for questions requiring multi-evidence synthesis.
Anthology ID:
2025.findings-acl.354
Volume:
Findings of the Association for Computational Linguistics: ACL 2025
Month:
July
Year:
2025
Address:
Vienna, Austria
Editors:
Wanxiang Che, Joyce Nabende, Ekaterina Shutova, Mohammad Taher Pilehvar
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
6811–6829
Language:
URL:
https://preview.aclanthology.org/mtsummit-25-ingestion/2025.findings-acl.354/
DOI:
10.18653/v1/2025.findings-acl.354
Bibkey:
Cite (ACL):
Bingsen Chen, Shenji Wan, Xi Ye, and Chen Zhao. 2025. Inter-Passage Verification for Multi-evidence Multi-answer QA. In Findings of the Association for Computational Linguistics: ACL 2025, pages 6811–6829, Vienna, Austria. Association for Computational Linguistics.
Cite (Informal):
Inter-Passage Verification for Multi-evidence Multi-answer QA (Chen et al., Findings 2025)
Copy Citation:
PDF:
https://preview.aclanthology.org/mtsummit-25-ingestion/2025.findings-acl.354.pdf