DeepWeaver: Bridging the Evidence Synthesis Gap in Open-Ended Question Answering

Xujia Wang, Yizhe Zhang, Bin Xu, Lei Hou, Juanzi Li


Abstract
Retrieve-then-generate pipelines are commonly used to produce deep-research answers for open-ended questions, but retrieval alone is insufficient: LLMs must organize noisy and fragmented evidence into comprehensive, well-cited answers. We refer to this process as **evidence synthesis**. However, direct generation often underuses evidence, misaligns citations, and collapses diverse information into shallow summaries, exposing an evidence synthesis gap between retrieval and generation. Thus, we propose **DeepWeaver**, a novel framework that weaves noisy retrieved evidence into comprehensive answers by maintaining Thought Block Chains (TBCs), a structured representation that groups claims, salient information, keywords, and supporting evidence. DeepWeaver uses subordinate TBCs to inspect residual evidence, commit TBC revisions, and discover new claims before final generation. We evaluate DeepWeaver on open-ended QA over both knowledge bases and the web, and introduce **LoQA**, a high-density benchmark for evidence synthesis. Across multiple LLMs, DeepWeaver improves content sufficiency, citation grounding, and detail preservation on LoQA, while achieving deeper insights and higher citation quality on DeepResearch Bench. These results show that evidence weaving is an effective mechanism for bridging retrieval and generation in open-ended QA.
Anthology ID:
2026.findings-emnlp.961
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
20307–20354
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.961/
DOI:
10.18653/2026.findings-emnlp.961
Bibkey:
Cite (ACL):
Xujia Wang, Yizhe Zhang, Bin Xu, Lei Hou, and Juanzi Li. 2026. DeepWeaver: Bridging the Evidence Synthesis Gap in Open-Ended Question Answering. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 20307–20354, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
DeepWeaver: Bridging the Evidence Synthesis Gap in Open-Ended Question Answering (Wang et al., Findings 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.findings-emnlp.961.pdf