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Ontologies and The Real World. Reading: Papers under “Knowledge Representation” under LINKS. Agenda. Taxonomies sample upper level models Different kinds of knowledge Gazetteers Defining concepts An exercise in ontology development

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ontologies and the real world

Ontologies and The Real World

Reading: Papers under “Knowledge Representation” under LINKS

agenda
Agenda
  • Taxonomies
      • sample upper level models
      • Different kinds of knowledge
      • Gazetteers
  • Defining concepts
  • An exercise in ontology development
  • Using ontologies to help in natural language learning tasks
upper level models
Upper Level Models
  • CYC
  • WordNet
  • Omega
  • Suomo
slide5
CYC
  • http://opencyc.org
wordnet http wordnet princeton edu
WordNethttp://wordnet.princeton.edu
  • 118,000 different words
  • 90,000 different word senses
  • 166,000 different word/sense pairs
relations in wordnet
Relations in WordNet
  • Synonymy – antonymy
  • Hyponomy – hypernomy
  • Meronymy – holonymy
  • Tryponomy
  • Entailment relations
omega
OMEGA
  • http://omega.isi.edu/doc/browsers.html
suggested upper merged ontology sumo
Suggested Upper Merged Ontology (SUMO)
  • Collaborative effort across sites
  • Will provide definitions for standard terms
  • Will provide a foundation for domain specific efforts
  • Will ultimately contain 1000-2500 terms and 10 definitions per term
questions
Questions
  • What criteria should we use in deciding what goes into the upper level?
  • How do we know if we were right?
  • How well do these hierarchies do at capturing general distinctions?
other kinds of knowledge
Other kinds of knowledge
  • Professions
  • Locations
using knowledge in machine learning
Using knowledge in machine learning
  • Categorization of text
  • We learn from the association of words with categories
  • Could world knowledge yield better results?
newsblaster
Newsblaster
  • http://newsblaster.cs.columbia.edu