Negation: A Pink Elephant in the Large Language Models' Room?

Warning

This publication doesn't include Institute of Computer Science. It includes Faculty of Informatics. Official publication website can be found on muni.cz.
Authors

VRABCOVÁ Tereza KADLČÍK Marek SOJKA Petr ŠTEFÁNIK Michal SPIEGEL Michal

Year of publication 2025
Type Article in Proceedings
Conference Findings of the Association for Computational Linguistics: EMNLP 2025
MU Faculty or unit

Faculty of Informatics

Citation
web Odkaz na preprint přijatého paperu
Keywords textual entailment; robustness; scaling; evaluation; natural language inference; multilingualism; multilingual corpora; lexical semantic change; negation
Description Negations are key to determining sentence meaning, making them essential for logical reasoning. Despite their importance, negations pose a substantial challenge for large language models (LLMs) and remain underexplored. We constructed and published two new textual entailment datasets NoFEVER-ML and NoSNLI-ML in four languages (English, Czech, German, and Ukrainian) with examples differing in negation. It allows investigation of the root causes of the negation problem and its exemplification: how popular LLM model properties and language impact their inability to handle negation correctly. Contrary to previous work, we show that increasing the model size may improve the models' ability to handle negations. Furthermore, we find that both the models' reasoning accuracy and robustness to negation are language-dependent and that the length and explicitness of the premise have an impact on robustness. There is better accuracy in projective language with fixed order, such as English, than in non-projective ones, such as German or Czech. Our entailment datasets pave the way to further research for explanation and exemplification of the negation problem, minimization of LLM hallucinations, and improvement of LLM reasoning in multilingual settings.
Related projects:

You are running an old browser version. We recommend updating your browser to its latest version.

More info