A Comprehensive Taxonomy of Negation for NLP and Neural Retrievers
Roxana Petcu, Samarth Bhargav, Maarten de Rijke, Evangelos Kanoulas
Abstract
Understanding and solving complex reasoning tasks is vital for addressing the information needs of a user. Although dense neural models learn contextualised embeddings, they underperform on queries containing negation. To understand this phenomenon, we study negation in traditional neural information retrieval and LLM-based models. We (1) introduce a taxonomy of negation that derives from philosophical, linguistic, and logical definitions; (2) generate two benchmark datasets that can be used to evaluate the performance of neural information retrieval models and to fine-tune models for a more robust performance on negation; and (3) propose a logic-based classification mechanism that can be used to analyze the performance of retrieval models on existing datasets. Our taxonomy produces a balanced data distribution over negation types, providing a better training setup that leads to faster convergence on the NevIR dataset. Moreover, we propose a classification schema that reveals the coverage of negation types in existing datasets, offering insights into the factors that might affect the generalization of fine-tuned models on negation. Our code is publicly available on GitHub, and the datasets are available on HuggingFace.- Anthology ID:
- 2025.findings-emnlp.839
- Volume:
- Findings of the Association for Computational Linguistics: EMNLP 2025
- Month:
- November
- Year:
- 2025
- Address:
- Suzhou, China
- Editors:
- Christos Christodoulopoulos, Tanmoy Chakraborty, Carolyn Rose, Violet Peng
- Venue:
- Findings
- SIG:
- Publisher:
- Association for Computational Linguistics
- Note:
- Pages:
- 15511–15533
- Language:
- URL:
- https://preview.aclanthology.org/ingest-luhme/2025.findings-emnlp.839/
- DOI:
- 10.18653/v1/2025.findings-emnlp.839
- Cite (ACL):
- Roxana Petcu, Samarth Bhargav, Maarten de Rijke, and Evangelos Kanoulas. 2025. A Comprehensive Taxonomy of Negation for NLP and Neural Retrievers. In Findings of the Association for Computational Linguistics: EMNLP 2025, pages 15511–15533, Suzhou, China. Association for Computational Linguistics.
- Cite (Informal):
- A Comprehensive Taxonomy of Negation for NLP and Neural Retrievers (Petcu et al., Findings 2025)
- PDF:
- https://preview.aclanthology.org/ingest-luhme/2025.findings-emnlp.839.pdf