TY - JOUR AU - Hu, Anwen AU - Dou, Zhicheng AU - Nie, Jian-Yun AU - Wen, Ji-Rong PY - 2020/04/03 Y2 - 2024/03/29 TI - Leveraging Multi-Token Entities in Document-Level Named Entity Recognition JF - Proceedings of the AAAI Conference on Artificial Intelligence JA - AAAI VL - 34 IS - 05 SE - AAAI Technical Track: Natural Language Processing DO - 10.1609/aaai.v34i05.6304 UR - https://ojs.aaai.org/index.php/AAAI/article/view/6304 SP - 7961-7968 AB - <p>Most state-of-the-art named entity recognition systems are designed to process each sentence within a document independently. These systems are easy to confuse entity types when the context information in a sentence is not sufficient enough. To utilize the context information within the whole document, most document-level work let neural networks on their own to learn the relation across sentences, which is not intuitive enough for us humans. In this paper, we divide entities to multi-token entities that contain multiple tokens and single-token entities that are composed of a single token. We propose that the context information of multi-token entities should be more reliable in document-level NER for news articles. We design a fusion attention mechanism which not only learns the semantic relevance between occurrences of the same token, but also focuses more on occurrences belonging to multi-tokens entities. To identify multi-token entities, we design an auxiliary task namely ‘Multi-token Entity Classification’ and perform this task simultaneously with document-level NER. This auxiliary task is simplified from NER and doesn't require extra annotation. Experimental results on the CoNLL-2003 dataset and OntoNotes<sub>nbm</sub> dataset show that our model outperforms state-of-the-art sentence-level and document-level NER methods.</p> ER -