{"type":"ScholarlyArticle","title":"Locating Complex Named Entities in Web Text","authors":[{"name":"Doug Downey","slug":"doug-downey","given":"Doug","family":"Downey","affiliation":""},{"name":"Matthew Broadhead","slug":"matthew-broadhead","given":"Matthew","family":"Broadhead","affiliation":""},{"name":"Oren Etzioni","slug":"oren-etzioni","given":"Oren","family":"Etzioni","affiliation":""}],"abstract":"Named Entity Recognition (NER) is the task of locating and classifying names in text. In previous work, NER was limited to a small number of pre-defined entity classes (e.g., people, locations, and organizations). However, NER on the Web is a far more challenging problem. Complex names (e.g., film or book titles) can be very difficult to pick out precisely from text. Further, the Web contains a wide variety of entity classes, which are not known in advance. Thus, hand-tagging examples of each entity class is impractical. This paper investigates a novel approach to the first step in Web NER: locating complex named entities in Web text. Our key observation is that named entities can be viewed as a species of multi-word units, which can be detected by accumulating n-gram statistics over the Web corpus. We show that this statistical method's F1 score is 50% higher than that of supervised techniques including Conditional Random Fields (CRFs) and Conditional Markov Models (CMMs) when applied to complex names. The method also outperforms CMMs and CRFs by 117% on entity classes absent from the training data. Finally, our method outperforms a semi-supervised CRF by 73%.","doi":null,"url":"https://ijcai.org/proceedings/2007/439","pdf":"https://ijcai.org/proceedings/2007/0439.pdf","markdown":"https://ijcai.org/proceedings/2007/439.md","bibtex":"https://ijcai.org/proceedings/2007/bibtex/439","volume":{"slug":"2007","title":"Proceedings of the Twentieth International Joint Conference on Artificial Intelligence","short_title":"IJCAI 2007","url":"https://ijcai.org/proceedings/2007/","year":2007,"location":"Hyderabad, India","dates":"","editors":"Ramon López de Mántaras","isbn":"","publisher":"International Joint Conferences on Artificial Intelligence","doi_prefix":""},"section":null,"track":"","number":439,"pages":{"first":2733,"last":2738},"keywords":[],"videos":[],"references":[],"license_note":"Copyright International Joint Conferences on Artificial Intelligence."}