What 1,114 Documents Reveal About Schema-Driven Extraction: Models, Pipelines, and the Real-vs-Synthetic Gap

Frank Thomas, Andrei Vince


Abstract
Extracting structured data from documents is a core task in finance, insurance, legal, and healthcare, yet empirical studies comparing extraction approaches across domains remain scarce. We assemble a corpus of 1,114 documents across 12 categories spanning 8 domains, with 7,197 fields annotated with ground-truth values, and use it to study how extraction accuracy varies across models, pipeline architectures, and document sources. We evaluate with a type-aware methodology that scores every field as a correct extraction, a miss, a hallucination, or a correct absence, so that declining to extract is distinguished from extracting wrongly. Our central finding is that aggregate accuracy conceals critical divergence along every axis: synthetic documents overestimate accuracy by 38–45pp on insurance certificates (n=18 real documents); three models score within 1pp overall but diverge by 31pp per category; and two pipeline architectures diverge by 26pp on contracts—with the advantage not predicted by document length. An independently built extraction system, run under a protocol fixed in advance, agrees with our ground truth on 82–87% of fields across three models spanning two providers, providing evidence that the corpus is not calibrated to a single implementation. The corpus and evaluation tooling are released to enable reproducible comparison.
Anthology ID:
2026.emnlp-industry.56
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Pepa Atanasova, Gholamreza Haffari, Minghan Wang
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
928–940
Language:
URL:
https://aclanthology.org/2026.emnlp-industry.56/
DOI:
Bibkey:
Cite (ACL):
Frank Thomas and Andrei Vince. 2026. What 1,114 Documents Reveal About Schema-Driven Extraction: Models, Pipelines, and the Real-vs-Synthetic Gap. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track, pages 928–940, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
What 1,114 Documents Reveal About Schema-Driven Extraction: Models, Pipelines, and the Real-vs-Synthetic Gap (Thomas & Vince, EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-industry.56.pdf