mlsanityData to 7 Oct 2026

Learning Nested Named Entity Recognition from Flat Annotations

arXiv 2603.00840 ↗First posted 28 Feb 2026cs.CLcited by 0

Not on the map. Why?

Abstract (arXiv)

Nested named entity recognition identifies entities contained within other entities, but requires expensive multi-level annotation. While flat NER corpora exist abundantly, nested resources remain scarce. We investigate whether models can learn nested structure from flat annotations alone, evaluating four approaches: string inclusions (substring matching), entity corruption (pseudo-nested data), flat neutralization (reducing false negative signal), and a hybrid fine-tuned + LLM pipeline. On NEREL, a Russian benchmark with 29 entity types where 21% of entities are nested, our best combined method achieves 26.37% inner F1, closing 40% of the gap to full nested supervision. Code is available at https://github.com/fulstock/Learning-from-Flat-Annotations.

Key facts. No citing papers in the map yet (data through 7 Oct 2026). Builds on 17 of its 38 references that are in the map. First posted on arXiv 28 Feb 2026.

Builds on

17 of 38 references.

References · 17

  1. 2016Neural Architectures for Named Entity Recognitioncited by 548
  2. 2020Named Entity Recognition as Dependency Parsingcited by 150
  3. 2020An Analysis of Simple Data Augmentation for Named Entity Recognitioncited by 75
  4. 2020Named Entity Recognition without Labelled Data: A Weak Supervision Approachcited by 46
  5. 2021Distantly-Supervised Named Entity Recognition with Noise-Robust Learning and Language Model Augmented Self-Trainingcited by 41
  6. 2021A Sequence-to-Set Network for Nested Named Entity Recognitioncited by 40
  7. 2022Wojood: Nested Arabic Named Entity Corpus and Recognition using BERTcited by 32
  8. 2023A Family of Pretrained Transformer Language Models for Russiancited by 27
  9. 2015Morphological Analyzer and Generator for Russian and Ukrainian Languagescited by 25
  10. 2019NNE: A Dataset for Nested Named Entity Recognition in English Newswirecited by 25
  11. 2021DaN+: Danish Nested Named Entities and Lexical Normalizationcited by 19
  12. 2021NEREL: A Russian Dataset with Nested Named Entities, Relations and Eventscited by 13
5 more
  1. 2022RuNNE-2022 Shared Task: Recognizing Nested Named Entitiescited by 8
  2. 2024Facilitating large language model Russian adaptation with Learned Embedding Propagationcited by 8
  3. 2023Impact of Tokenization on LLaMa Russian Adaptationcited by 5
  4. 2023A Benchmark of Nested Named Entity Recognition Approaches in Historical Structured Documentscited by 3
  5. 2022Recognizing Nested Entities from Flat Supervision: A New NER Subtask, Feasibility and Challengescited by 2

Built on by

Not cited yet.