方法对比

	命名实体识别 (NER)	信息抽取	关系抽取
领域	文本挖掘	文本挖掘	文本挖掘
方法族	Process / pipeline	Process / pipeline	Process / pipeline
起源年份	—	—	—
提出者	—	—	—
类型	NLP sequence-labelling task	NLP structured-information task	NLP information-extraction task
开创性文献	Nadeau, D. & Sekine, S. (2007). A survey of named entity recognition. Lingvisticae Investigationes.	Cowie, J. & Lehnert, W. (1996). Information Extraction. Communications of the ACM.	Zelenko, D., Aone, C. & Richardella, A. (2003). Kernel Methods for Relation Extraction. Journal of Machine Learning Research, 3, 1083-1106.
别名	NER, entity tagging, Adlandırılmış Varlık Tanıma (NER)	IE, structured information extraction, Bilgi Çıkarma (Information Extraction)	semantic relation extraction, İlişki Çıkarma (Relation Extraction)
相关	3	4	4
摘要	Named entity recognition (NER) is a natural-language-processing task that automatically detects and labels entities in text — such as people, organisations, locations, and dates. Surveyed by Nadeau and Sekine (2007) and later advanced with neural architectures by Lample et al. (2016), it turns free-running text into tagged spans that downstream tools can use.	Information extraction (IE) is a natural-language-processing task that converts unstructured text into structured information — such as events, relations, and attributes — so that facts buried in free-form documents become machine-readable records. The task was consolidated in early surveys by Cowie and Lehnert (1996) and later by Grishman (2012).	Relation extraction is a natural-language-processing task that detects and classifies the semantic relations that hold between entities mentioned in text. Building on early kernel-based methods (Zelenko and colleagues, 2003) and later neural matching approaches (Baldini Soares and colleagues, 2019), it turns free-form text into structured facts of the form entity–relation–entity.