LongDA: Benchmarking LLM Agents for Long-Document Data Analysis

Yiyang Li, Zheyuan Zhang, Tianyi Ma, Zehong Wang, Keerthiram Murugesan, Chuxu Zhang, Yanfang Ye


Abstract
We introduce LongDA, a data analysis benchmark for evaluating LLM-based agents under documentation-intensive analytical workflows. In contrast to existing benchmarks that assume well-specified schemas and inputs, LongDA targets real-world settings in which navigating long documentation and complex data is the primary bottleneck. To this end, we manually curate raw data files, long and heterogeneous documentation, and expert-written publications from 17 publicly available U.S. national surveys, from which we extract 505 analytical queries grounded in real analytical practice. Solving these queries requires agents to first retrieve and integrate key information from multiple unstructured documents before performing multi-step computations and writing executable code, which remains challenging for existing data analysis agents. To support the systematic evaluation under this setting, we develop LongTA, a tool-augmented agent framework that enables document access, retrieval, and code execution, and evaluate a range of proprietary and open-source models. Our experiments reveal substantial performance gaps even among state-of-the-art models, highlighting the challenges researchers should consider before applying LLM agents for decision support in real-world, high-stakes analytical settings.
Anthology ID:
2026.docinsights-1.9
Volume:
The Proceedings of Workshop on Document Intelligence and Understanding
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Santosh T.Y.S.S., Amit Agarwal, Vivek Gupta, Yova Kementchedjhieva, Aparna Garimella, Yufang Hou
Venues:
DocInsights | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
112–137
Language:
URL:
https://aclanthology.org/2026.docinsights-1.9/
DOI:
Bibkey:
Cite (ACL):
Yiyang Li, Zheyuan Zhang, Tianyi Ma, Zehong Wang, Keerthiram Murugesan, Chuxu Zhang, and Yanfang Ye. 2026. LongDA: Benchmarking LLM Agents for Long-Document Data Analysis. In The Proceedings of Workshop on Document Intelligence and Understanding, pages 112–137, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
LongDA: Benchmarking LLM Agents for Long-Document Data Analysis (Li et al., DocInsights 2026)
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PDF:
https://aclanthology.org/2026.docinsights-1.9.pdf