KnowItAll System

The KnowItAll System is a Web Information Extraction System.

• AKA: KnowItAll, KnowItAll Web IE System.
• Context:
  • It implements the KnowItAll Algorithm, a Semi-Supervised Named Entity Recognition Algorithm.
  • It is a Knowledge Base that populates its facts, concepts, and relationships by extracting the information from the web.
  • It is intended to be scalability and have high throughput in order to access the information on the Web.
    • It avoids the use of deep parsing techniques.
  • It is divided into four components:
    • Extractor,
    • Search Engine Interface,
    • Assessor,
    • Database.
  • It requires a set of generic Extraction Pattern seeds (not Instance seeds).
  • It includes a predefined set of topics (ontology) such as:
    • cities, states, countries, actors and films.
  • It is developed at the University of Washington.
  • It is based on the KnowItAll Hypothesis that: "Extractions drawn more frequently from distinct sentences in a corpus are more likely to be correct.
• Counter-Example(s):
  • TextRunner System.
  • Opine System.
• See: Open Information Extraction. ReVerb System.

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References

• http://www.cs.washington.edu/research/knowitall/

2008

• (Downey, 2008) ⇒ Doug Downey. (2008). “Redundancy in Web-scale Information Extraction: Probabilistic Model and Experimental Results." PhD Thesis, University of Washington.

2005

• (Etzioni et al., 2005) ⇒ Oren Etzioni, Michael J. Cafarella, Doug Downey, Ana-Maria Popescu, Tal Shaked, Stephen Soderland, Daniel S. Weld, and Alexander Yates. (2005). “Unsupervised Named-Entity Extraction from the Web: An Experimental Study.” In: Artificial Intelligence, 165(1).
• (Downey et al., 2005) ⇒ Doug Downey, Oren Etzioni, and Stephen Soderland. (2005). “A Probabilistic Model of Redundancy in Information Extraction." Proceedings of the Nineteenth International Joint Conference on Artificial Intelligence (IJCAI-2005).

2004

• (Etzioni et al., 2004) ⇒ Oren Etzioni, Michael J. Cafarella, Doug Downey, S. Kok, Ana-Maria Popescu, Tal Shaked, Stephen Soderland, Daniel S. Weld, and Alexander Yates. (2004). “Web-scale Information Extraction in KnowItAll: (preliminary results).” In: Proceedings of the 13th International World Wide Web Conference (WWW 2004).

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