OntonotesNamedEntityRecognition(self, token_indexers:Dict[str,]=None, domain_identifier:str=None, coding_scheme:str='BIO', **kwargs) -> None

This DatasetReader is designed to read in the English OntoNotes v5.0 data for fine-grained named entity recognition. It returns a dataset of instances with the following fields:

tokens : TextField The tokens in the sentence. tags : SequenceLabelField A sequence of BIO tags for the NER classes.

Note that the "/pt/" directory of the Onotonotes dataset representing annotations on the new and old testaments of the Bible are excluded, because they do not contain NER annotations.


  • token_indexers : Dict[str, TokenIndexer], optional
  • We similarly use this for both the premise and the hypothesis. See :class:TokenIndexer.
  • __Default is {"tokens"__: SingleIdTokenIndexer()}.
  • domain_identifier : str, (default = None) A string denoting a sub-domain of the Ontonotes 5.0 dataset to use. If present, only conll files under paths containing this domain identifier will be processed.
  • coding_scheme : str, (default = None). The coding scheme to use for the NER labels. Valid options are "BIO" or "BIOUL".


A Dataset of Instances for Fine-Grained NER.


OntonotesNamedEntityRecognition.text_to_instance(self, tokens:List[], ner_tags:List[str]=None) ->

We take pre-tokenized input here, because we don't have a tokenizer in this class.