Named entity recognition(NER),as a core task in natural language processing,finds ex-tensive applications in information extraction,question answering systems,machine translation,and more.Firstly,descriptions and summaries are provided for rule-based,dictionary-based,and statistical machine learning methods.Subsequently,an overview of NER models based on deep learning,including supervised,distant supervision,and Transformer-based approaches,is presented.Particularly,recent advancements in Transformer architecture and its related models in the field of natural language process-ing are elucidated,such as Transformer-based masked language modeling and autoregressive language modeling,including BERT,T5,and GPT.Furthermore,brief discussions are conducted on data trans-fer learning and model transfer learning methods applied to NER.Finally,challenges faced by NER tasks and future development trends are summarized.
named entity recognitionmachine learningdeep learningtransfer learningnatural lan-guage processing