Challenge: Existing methods to recognize named entities have been criticized for their performance on flat NER but fail to handle nested entities.
Approach: They propose to use a span-based constituency parser to tackle nested NER . they use lexicalized constituency trees to model nesting entities .
Outcome: The proposed method achieves state-of-the-art performance on ACE2004, ACE2005 and NNE, and competitive performance on the GENIA platform.

Similar Papers

Bottom-Up Constituency Parsing and Nested Named Entity Recognition with Pointer Networks (2022.acl-long)

Copied to clipboard

Challenge: Constituency parsing and nested named entity recognition (NER) are similar tasks since they aim to predict a collection of nesting and non-crossing spans.
Approach: They propose a model that uses a pointer network to predict a constituency tree's boundary . constituency parsing is an important task in natural language processing .
Outcome: The proposed model achieves state-of-the-art performance on PTB among all BERT-based models and competitive performance on CTB7 in constituency parsing.
Nested Named Entity Recognition as Single-Pass Sequence Labeling (2025.findings-emnlp)

Copied to clipboard

Challenge: nested named entity recognition is a sequence labeling task that can be trained using any off-the-shelf sequence labelling library.
Approach: They use prior work that linearizes constituency structures to create a nested named entity recognition task.
Outcome: The proposed method reduces the complexity of the predicted nested entity recognition problem to a simple token classification task.
Hierarchical Region Learning for Nested Named Entity Recognition (2020.findings-emnlp)

Copied to clipboard

Challenge: Existing methods to recognize entities recursively from innermost to outermost are based on brute force and two-stage paradigms, often leading to cascaded errors.
Approach: They propose a hierarchical region learning framework to automatically generate a tree hierarchy of candidate regions with nearly linear complexity and incorporate structure information into the region representation for better classification.
Outcome: Experiments on benchmark datasets ACE-2005, GENIA and JNLPBA show that the proposed framework performs better than state-of-the-art models.
Deep Exhaustive Model for Nested Named Entity Recognition (D18-1)

Copied to clipboard

Challenge: Named entity recognition (NER) is a task of finding entities with specific semantic types such as Protein, Cell, and RNA in text.
Approach: They propose a deep neural model for nested named entity recognition . they enumerate all possible regions or spans as potential entity mentions .
Outcome: The proposed model outperforms state-of-the-art models on nested and flat NER . it achieves 77.1% and 78.4% respectively in terms of F-score, without external knowledge resources.
Named Entity Recognition as Dependency Parsing (2020.acl-main)

Copied to clipboard

Challenge: Named Entity Recognition (NER) is a fundamental task in Natural Language Processing, concerned with identifying spans of text expressing references to entities.
Approach: They propose a method to handle both types of NEs in one system by using a biaffine dependency parsing model which scores pairs of start and end tokens in a sentence.
Outcome: The proposed model performs well on 8 corpora and achieves accuracy gains of up to 2.2 percentage points.
Nested Named Entity Recognition with Span-level Graphs (2022.acl-long)

Copied to clipboard

Challenge: Named entity recognition is one of the major subtasks of information extraction for extracting categorized named entities from unstructured text.
Approach: They propose to use retrieval-based span-level graphs to connect spans and entities in the training data based on n-gram features to integrate information of similar neighbor entities into the span representation.
Outcome: The proposed method achieves general improvements on all three benchmarks and special superiority on low frequency entities.
Learning Nested Named Entity Recognition from Flat Annotations (2026.eacl-srw)

Copied to clipboard

Challenge: Named entity recognition (NER) requires expensive multi-level annotation.
Approach: They evaluate four approaches to learning nested structure from flat annotations alone . on NEREL, a Russian benchmark, they find the best method achieves 26.37% inner F1 .
Outcome: The proposed method closes 40% of the gap to full nested supervision on a Russian benchmark with 29 entity types where 21% of entities are nest.
Locate and Label: A Two-stage Identifier for Nested Named Entity Recognition (2021.acl-long)

Copied to clipboard

Challenge: Named entity recognition (NER) is a well-studied task in natural language processing.
Approach: They propose a method that generates span proposals and labels them with categories . they use boundary information of entities and partially matched spans to locate them .
Outcome: The proposed method outperforms state-of-the-art models on nested NER datasets.
A Unified MRC Framework for Named Entity Recognition (2020.acl-main)

Copied to clipboard

Challenge: Named entity recognition is divided into nested NER and flat NER depending on whether entities are nesting.
Approach: They propose to formulate named entity recognition task as machine reading comprehension task instead of sequence labeling problem .
Outcome: The proposed framework achieves vast amount of performance boost over current models on nested and flat NER datasets.
Neural Architectures for Nested NER through Linearization (P19-1)

Copied to clipboard

Challenge: a nested named entity recognition (NER) is a set of entities that can overlap and be labeled with more than one label.
Approach: They propose two neural network architectures for nested named entity recognition . they propose to model nesting entities as multilabels and predict a sequence-to-sequence problem .
Outcome: The proposed methods outperform the state-of-the-art on four corpora . the proposed models also improve on the recently published contextual embeddings .

What is GenGO?

GenGO is an NLP powered publication search system. It currenctly indexes 30k+ papers from ACL Anthology, and implements multi-aspect summarization, semantic search, and more!

Information

About
Limitations