kNN-NER: Named Entity Recognition with Nearest Neighbor Search

The repository contains the code of the recent research KNN-NER.

kNN-NER: Named Entity Recognition with Nearest Neighbor Search

Shuhe Wang, Xiaoya Li, Yuxian Meng, Rongbin Ouyang, Jiwei Li, Guoyin Wang

If you find this repo helpful, please cite the following:

@article{wang2022k,
  title={$ k $ NN-NER: Named Entity Recognition with Nearest Neighbor Search},
  author={Wang, Shuhe and Li, Xiaoya and Meng, Yuxian and Zhang, Tianwei and Ouyang, Rongbin and Li, Jiwei and Wang, Guoyin},
  journal={arXiv preprint arXiv:2203.17103},
  year={2022}
}

Requirements

1. python 3.6+
2. If you are working on a GPU machine, please install GPU version torch>=1.7.1, more details for PyTorch can be found on the Official Website

We provide two kinds of vanilla NER model for kNN-NER:

1. BERT and RoBERTa: Requirements for BERT and RoBERTa are same as the repo MRC, you can run the command pip install -r ./bert/requirements.txt or look at MRC for more details.
2. ChineseBERT: Requirements for ChineseBERT are same as the repo ChineseBERT, you can run the command pip install -r ./ChineseBert/requirements.txt or look at ChineseBERT for more details.

Datasets

The preprocessed datasets used for KNN-NER can be found here. Each dataset is splited into three fileds train/valid/test. The file ner_labels.txt in each dataset contains all the labels within it and you can generate it by running the script python ./get_labels.py --data-dir DATADIR --file-name NAME.

The Vanilla NER model

Pre-trained NER Model

You can direct download a pre-trained ner model as the vanilla NER model and only follow the two step Building Datastore and Inference to reproduce the results of KNN-NER.

Based on BERT

For pre-trained BERT NER model, you can use Baseline:BERT-Tagger.

Based on ChineseBERT

For pre-trained ChineseBERT NER model, you can use NER Task.

Training Models For NER

Downloading Backbone Models

There are five version models for Chinese datasets and three version models for English datasets, you can download them following:

Zh Models

• BERT-Base: https://huggingface.co/bert-base-chinese
• RoBERTa-Base: https://huggingface.co/hfl/chinese-roberta-wwm-ext
• RoBERTa-Large: https://huggingface.co/hfl/chinese-roberta-wwm-ext-large
• ChineseBERT-Base: https://huggingface.co/ShannonAI/ChineseBERT-base
• ChineseBERT-Large: https://huggingface.co/ShannonAI/ChineseBERT-large

En Models

• BERT-Base: https://huggingface.co/bert-base-cased
• BERT-Large: https://huggingface.co/bert-large-cased
• RoBERTa-Large: https://huggingface.co/roberta-large

Training

You can train a new NER model following the script ./ChineseBert/KNN-NER/DATASET_NAME/only_ner.sh with ChineseBERT as the backbone and the script ./bert/DATASET_NAME/only_ner.sh with BERT or RoBERTa as the backbone. The DATASET_NAME is the combination of the used dataset and backbone model, such as weibo_bert_base_zh means training a NER model for dataset Weibo with model bert-base-chinese as the backbone. Note that you need to change DARA_DIR, FILE_NAME, SAVE_PATH and BERT_PATH to your own path.

Building Datastore

To build datastore for you trained or pre-trained NER model, you can run the script ./ChineseBert/KNN-NER/DATASET_NAME/find_knn.sh or ./bert/DATASET_NAME/find_knn.sh. The meaning of DATASET_NAME is same as the above Training setp, wihch is the combination of the used dataset and backbone model.

Inference

Code for inference using the KNN-NER model can be found in ./ChineseBert/KNN-NER/DATASET_NAME/knn_ner.sh or ./bert/DATASET_NAME/knn_ner.sh.

Results

Date 2022.03.29, the results are same as the paper here.

Chinese OntoNotes 4.0

Model	Test Precision	Test Recall	Test F1
Base Model	----	----	----
BERT-Base	78.01	80.35	79.16
BERT-Base+kNN	80.23	81.60	80.91 (+1.75)
RoBERTa-Base	80.43	80.30	80.37
RoBERTa-Base+kNN	79.65	82.60	81.10 (+0.73)
ChineseBERT-Base	80.03	83.33	81.65
ChineseBERT-Base+kNN	81.43	82.58	82.00 (+0.35)
Large Model	----	----	----
RoBERTa-Large	80.72	82.07	81.39
RoBERTa-Large+kNN	79.87	83.17	81.49 (+0.10)
ChineseBERT-Large	80.77	83.65	82.18
ChineseBERT-Large+kNN	81.68	83.46	82.56 (+0.38)

Chinese MSRA

Model	Test Precision	Test Recall	Test F1
Base Model	----	----	----
BERT-Base	94.97	94.62	94.80
BERT-Base+kNN	95.34	94.64	94.99 (+0.19)
RoBERTa-Base	95.27	94.66	94.97
RoBERTa-Base+kNN	95.47	94.79	95.13 (+0.16)
ChineseBERT-Base	95.39	95.39	95.39
ChineseBERT-Base+kNN	95.73	95.27	95.50 (+0.11)
Large Model	----	----	----
RoBERTa-Large	95.87	94.89	95.38
RoBERTa-Large+kNN	95.96	95.02	95.49 (+0.11)
ChineseBERT-Large	95.61	95.61	95.61
ChineseBERT-Large+kNN	95.83	95.68	95.76 (+0.15)

Chinese Weibo

Model	Test Precision	Test Recall	Test F1
Base Model	----	----	----
BERT-Base	67.12	66.88	67.33
BERT-Base+kNN	70.07	67.87	68.96 (+1.63)
RoBERTa-Base	68.49	67.81	68.15
RoBERTa-Base+kNN	67.52	69.81	68.65 (+0.50)
ChineseBERT-Base	68.27	69.78	69.02
ChineseBERT-Base+kNN	68.97	73.71	71.26 (+2.24)
Large Model	----	----	----
RoBERTa-Large	66.74	70.02	68.35
RoBERTa-Large+kNN	69.36	70.53	69.94 (+1.59)
ChineseBERT-Large	68.75	72.97	70.80
ChineseBERT-Large+kNN	75.00	69.29	72.03 (+1.23)

English CoNLL 2003

Model	Test Precision	Test Recall	Test F1
Base Model	----	----	----
BERT-Base	90.69	91.96	91.32
BERT-Base+kNN	91.50	91.58	91.54 (+0.22)
Large Model	----	----	----
BERT-Large	91.54	92.79	92.16
BERT-Large+kNN	92.26	92.43	92.40 (+0.24)
RoBERTa-Large	92.77	92.81	92.76
RoBERTa-Large+kNN	92.82	92.99	92.93 (+0.17)

English OntoNotes 5.0

Model	Test Precision	Test Recall	Test F1
Base Model	----	----	----
BERT-Base	85.09	85.99	85.54
BERT-Base+kNN	85.27	86.13	85.70 (+0.16)
Large Model	----	----	----
BERT-Large	85.84	87.61	86.72
BERT-Large+kNN	85.92	87.84	86.87 (+0.15)
RoBERTa-Large	86.59	88.17	87.37
RoBERTa-Large+kNN	86.73	88.29	87.51 (+0.14)

Contact

If you have any question about our paper/code/modal/data...

Please feel free to discuss through github issues or emails.

You can send emails to shuhe_wang@shannonai.com