ElementCheck: Complexity-Aware Long-Form Text Factuality Evaluation via Sentence Elements

Xinming Wang, Haoran Du, Yi Chen, Xueqing Chen, Jian Xu, Hong-Ming Yang, Han Hu, Yulong Chen, Cheng-Lin Liu, Xu-Yao Zhang


Abstract
Existing long-form factuality evaluation relies on the decompose-retrieve-verify pipeline. However, the pipeline suffers from noise from claim decomposition and fixed verification granularity, resulting in unreliable results. We propose ElementCheck, a complexity-aware framework that verifies long-form outputs via sentence elements. Instead of uniformly decomposing sentences into atomic sub-claims, ElementCheck extracts entity pairs that are explicitly linked through verifiable connections in the original sentence as elements, and organizes these into an element graph. The graph topology provides a structural signal for estimating sentence complexity, enabling direct verification for simple sentences and targeted element-level refinement and verification for complex ones. To support fine-grained evaluation, we construct a new benchmark FastFact-Sent by mapping isolated claims from FastFact-Bench back to their source sentences. Experiments on FastFact-Sent and two domain-specific benchmarks show ElementCheck consistently improves factuality verification across five backbone models while maintaining a favorable accuracy-cost trade-off. Further analyses demonstrate that complexity-aware verification reduces unnecessary re-verification and maintains stability across different backbones. The code is available at Here.
Anthology ID:
2026.findings-emnlp.868
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:
18336–18363
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URL:
https://aclanthology.org/2026.findings-emnlp.868/
DOI:
Bibkey:
Cite (ACL):
Xinming Wang, Haoran Du, Yi Chen, Xueqing Chen, Jian Xu, Hong-Ming Yang, Han Hu, Yulong Chen, Cheng-Lin Liu, and Xu-Yao Zhang. 2026. ElementCheck: Complexity-Aware Long-Form Text Factuality Evaluation via Sentence Elements. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 18336–18363, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
ElementCheck: Complexity-Aware Long-Form Text Factuality Evaluation via Sentence Elements (Wang et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.868.pdf