OWL: Capturing Semantic Information using a standardized web ontology language

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OWL Capturing Semantic Information using a
standardized web ontology language

• By Aditya Kalyanpur, Jennifer Golbeck, Jay
  Banerjee, James Hendler
• Presented by Arjun Krishnamurthy

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Semantic Web

• An extension of the current World Wide Web
• Machine understandable data to enable computers
  to participate on the Web in new ways

People
Groups
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The intelligence is in the connections
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The intelligence is in the connections
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Semantic Web

• Tim Berners-Lee s view of the semantic web
• I have a dream for the Web in which computers
  become capable of analyzing all the data on the
  Web the content, links, and transactions
  between people and computers. A Semantic Web,
  which should make this possible, has yet to
  emerge, but when it does, the day-to-day
  mechanisms of trade, bureaucracy and our daily
  lives will be handled by machines talking to
  machines. The intelligent agents people have
  touted for ages will finally materialize.

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Ontology

• Branch of metaphysics concerned with the nature
  and relations of being (Merriam-Webster)
• Has its roots in the philosophy of Socrates,
  Plato, Aristotle.
• It is the science of what is, of the kinds and
  structures of objects, properties and relations
  in every area of reality
• It deals with the precise utilization of words as
  descriptors of entities or realities

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Ontologies in Natural Language Processing

• The formal nature of ontologies make them
  amenable to machine-readability and provides well
  defined semantics for the terms defined by them
• Computer programs can manipulate, transform and
  draw new inferences from the information
• NLP systems such as Information Retrieval,
  Question-Answering Systems, Machine Translation,
  Language Understanding make use of Ontologies

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Standardized ontology language TimeLine
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OWL The Name

• OWL
• WEB ONTOLOGY LANGUAGE ought to have the acronym
  WOL
• Some believe OWL is a reference to the
  misspelling by the above character although W3C
  claims there is no connection
• "Why not be inconsistent in at least one aspect
  of a language which is all about consistency?
  Gus Schreiber

A character from Winnie the Pooh books always
(mis)spelled his name as WOL
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OWL Characteristics

• Built on top of RDF (Resource Description
  Framework)
• Provides the capability of creating Classes,
  Properties and Instances
• Extends functionality of RDF/RDFS with its
  ability to create local range restrictions
• OWL can implement Set operations union,
  intersection, complements and disjointness
• Also defines Cardinalities

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Example 1
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Example 1 RDF Graph
The RDF Graph of Person
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Example 2 Range Restriction

• Eats

Person
Vegetarian Food
Vegetarian
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Example 3 Disjointness
Person
Specify Disjointness
Dead
Alive
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Example 4 Cardinality

• Twins means exactly 2 children
• Bilingual person must speak at the least 2
  languages
• There can be only 7 deadly sins

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OWL Sublanguages

• OWL Lite easy to use and an entry level
  ontology language for semantic web application
  developers (although not used widely)
• OWL DL Includes all OWL language constructs,
  but they can be used only under certain
  restrictions (for example, number restrictions
  may not be placed upon properties which are
  declared to be transitive).
• OWL Full Most powerful and provides freedom in
  domain modeling while retaining compatibility
  with RDFS

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Emerging Applications using OWL

• KnOWLer System Information management utility
  with sophisticated inferencing and query handling
  using OWL DL (description language)
• A natural language application developed in
  Universiti Sains Malaysia which performs word
  disambiguation
• SKOS-Core 1.0 RDF vocabulary
• W3Cs SWBPD Semantic Web Best Practices and
  Deployment Working Group aims to encourage dialog
  between Semantic Web Developers and members of
  the lexical semantics community
• FOAF project FOAF is about your place in the
  Web, and the Web's place in our world. FOAF is a
  simple technology that makes it easier to share
  and use information about people and their
  activities (eg. photos, calendars, weblogs), to
  transfer information between Web sites, and to
  automatically extend, merge and re-use it online
  (http//www.foaf-project.org/)

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Emerging Applications using OWL

• MINDSWAP semantic web portal developed in the
  University of Maryland, College park
  Demonstrates the joining of HTML, XHTML, CSS with
  semantic web technologies RDF, OWL to filter ,
  organize, sort web content from a large number of
  sources
• (http//www.mindswap.org/)
• Welcome to the first site on the semantic
  web

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MINDSWAP
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Conclusion

• OWL presents a relatively rich semantics for
  defining on-line ontologies that are both
  powerful for contemporary natural language
  processing projects and consistent with modern
  web standards and architecture.

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QUESTIONS