Hierarchical Contextualized Representation for Named Entity Recognition
Table 5: Ablation study on the three benchmark datasets.
['[EMPTY]', 'CoNLL03', 'CoNLL02', 'OntoNotes']
In this experiment, we individually adopt two hierarchical contextualized representations to enhance the representation of tokens: sentence-level representation for assigning the sentence state to each token and document-level representation for inference. We discover that both sentence-level and document-level representations enhance the baseline. By combing these two representations together, we get a larger gain of 0.36 / 0.43 / 0.40, respectively.