DeepSynth-Eval: Objectively Evaluating Information Consolidation in Deep Survey Writing

Hongzhi Zhang, Yuanze Hu, Tinghai Zhang, Jia Fu, Tao Wang, Junwei Jing, Zhaoxin Fan, Wei Bi, Ruiming Tang, Han Li, Guorui Zhou, Kun Gai


Abstract
The evolution of Large Language Models (LLMs) towards autonomous agents has catalyzed progress in Deep Research. While retrieval capabilities are well-benchmarked, the post-retrieval synthesis stage—where agents must digest massive amounts of context and consolidate fragmented evidence into coherent, long-form reports—remains under-evaluated due to the subjectivity of open-ended writing.To bridge this gap, we introduce DeepSynth-Eval, a benchmark designed to objectively evaluate information consolidation capabilities. We leverage high-quality survey papers as gold standards, reverse-engineer research requests, and construct Oracle Contexts from their bibliographies to isolate synthesis from retrieval noise. We propose a fine-grained evaluation protocol using General Checklists (for factual coverage) and Constraint Checklists (for structural organization), transforming subjective judgment into verifiable metrics. Experiments across 96 tasks reveal that synthesizing information from hundreds of references remains a significant challenge. Our results demonstrate that agentic "plan-then-write" workflows significantly outperform single-turn generation, effectively reducing hallucinations and improving adherence to complex structural constraints.
Anthology ID:
2026.findings-acl.1688
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
Findings
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Publisher:
Association for Computational Linguistics
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Pages:
33805–33822
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https://preview.aclanthology.org/ingest-acl/2026.findings-acl.1688/
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Cite (ACL):
Hongzhi Zhang, Yuanze Hu, Tinghai Zhang, Jia Fu, Tao Wang, Junwei Jing, Zhaoxin Fan, Wei Bi, Ruiming Tang, Han Li, Guorui Zhou, and Kun Gai. 2026. DeepSynth-Eval: Objectively Evaluating Information Consolidation in Deep Survey Writing. In Findings of the Association for Computational Linguistics: ACL 2026, pages 33805–33822, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
DeepSynth-Eval: Objectively Evaluating Information Consolidation in Deep Survey Writing (Zhang et al., Findings 2026)
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https://preview.aclanthology.org/ingest-acl/2026.findings-acl.1688.pdf
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