FactNLI: Dynamic and Automated Fact-Based Augmentation of NLI Benchmarks

Yihan Lu, Junzhe Zhang, Huixuan Zhang, Xiaojun Wan


Abstract
Natural Language Inference (NLI) is a core task for language understanding, yet existing NLI datasets are static and increasingly saturated, allowing current Large Language Models (LLMs) to perform well without fully revealing their capabilities and shortcomings. To address this problem, we propose a new data augmentation framework that automatically builds more challenging NLI datasets by iteratively fusing rich facts into the premise and hypothesis of an NLI instance. We use a strict fact filter to ensure that fused facts are non-contradictory and non-redundant. Applied to SNLI and MNLI, our augmentation substantially increases data length and complexity, and the performance of a range of LLMs on the augmented datasets drops significantly (up to 30%). Ablation experiments and human quality checks confirm the high quality of the generated data.
Anthology ID:
2026.findings-emnlp.1234
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:
26107–26127
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URL:
https://aclanthology.org/2026.findings-emnlp.1234/
DOI:
Bibkey:
Cite (ACL):
Yihan Lu, Junzhe Zhang, Huixuan Zhang, and Xiaojun Wan. 2026. FactNLI: Dynamic and Automated Fact-Based Augmentation of NLI Benchmarks. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 26107–26127, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
FactNLI: Dynamic and Automated Fact-Based Augmentation of NLI Benchmarks (Lu et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.1234.pdf