DEEPCHART: How Far are LLMs from Faithful Data-Science Chart Generation?

Jiahui Tang, Kuicai Dong, Dexun Li, Hongchao Gu, Haocheng Yu, Wei Han, Chen Zhang, Yong Liu, Hao Wang, Enhong Chen


Abstract
Faithful chart generation in real-world data-science workflows requires grounding visualizations in scattered evidence, computing chart-ready quantities, and rendering them accurately. Modern LLMs can produce visually plausible, instruction-compliant charts, yet data-level hallucinations remain difficult to detect in long, noisy, and multimodal contexts. To measure this gap, we introduce , an expert-annotated benchmark of 1,482 task-conditioned chart-generation instances drawn from real-world scientific papers, financial filings, and ecosystem reports. DEEPCHART formulates chart generation as an Extract–Reason–Visualize pipeline and evaluates source-data extraction, derived-data reasoning, and chart rendering stage by stage. Experiments with state-of-the-art models show that visually plausible charts often conceal data-level hallucinations, with extraction and reasoning errors common in realistic long and multimodal settings. These findings suggest that larger context windows alone are insufficient; faithful chart generation also requires reliable evidence extraction and quantitative reasoning before rendering.
Anthology ID:
2026.emnlp-main.1627
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:
37005–37031
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1627/
DOI:
Bibkey:
Cite (ACL):
Jiahui Tang, Kuicai Dong, Dexun Li, Hongchao Gu, Haocheng Yu, Wei Han, Chen Zhang, Yong Liu, Hao Wang, and Enhong Chen. 2026. DEEPCHART: How Far are LLMs from Faithful Data-Science Chart Generation?. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 37005–37031, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
DEEPCHART: How Far are LLMs from Faithful Data-Science Chart Generation? (Tang et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1627.pdf