Speculation detection for Chinese clinical notes: Impacts of word segmentation and embedding models.
Speculation detection for Chinese clinical notes: Impacts of word segmentation and embedding models.
复制标题
中文临床笔记的推测检测:分词和嵌入模型的影响
DOI:
10.1016/j.jbi.2016.02.011
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发表时间:
2016-04
影响因子:
4.5
通讯作者:
Lei J
中科院分区:
文献类型:
--
作者:
Zhang S;Kang T;Zhang X;Wen D;Elhadad N;Lei J
Speculations represent uncertainty towards certain facts. In clinical texts, identifying speculations is a critical step of natural language processing (NLP). While it is a nontrivial task in many languages, detecting speculations in Chinese clinical notes can be particularly challenging because word segmentation may be necessary as an upstream operation. The objective of this paper is to construct a state-of-the-art speculation detection system for Chinese clinical notes and to investigate whether embedding features and word segmentations are worth exploiting towards this overall task. We propose a sequence labeling based system for speculation detection, which relies on features from bag of characters, bag of words, character embedding, and word embedding. We experiment on a novel dataset of 36,828 clinical notes with 5,103 gold-standard speculation annotations on 2,000 notes, and compare the systems in which word embeddings are calculated based on word segmentations given by general and by domain specific segmenters respectively. Our systems are able to reach performance as high as 92.2% measured by F score. We demonstrate that word segmentation is critical to produce high quality word embedding to facilitate downstream information extraction applications, and suggest that a domain dependent word segmenter can be vital to such a clinical NLP task in Chinese language.