This file is licensed under the Creative Commons Attribution-NonCommercial 3.0 (CC BY-NC 3.0 ) Dr. Harald Sack Hasso Plattner Institute for IT Systems Engineering University of Potsdam Spring 2013 Semantic Web Technologies Lecture 4: Knowledge Representations I 04: Ontology Types
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This file is licensed under the Creative Commons Attribution-NonCommercial 3.0 (CC BY-NC 3.0)
Dr. Harald Sack
Hasso Plattner Institute for IT Systems Engineering
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
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Taxonomies
• also classification schema, nomenclature, …
• in science most times classification into (mono-)hierarchical sets (classes, subclasses, ...)
• (also) subject of biology:
• the arrangement of organisms into a classification according to similarities
Taxonomy: Definition of a hierarchical system of groups (from [greek] τασσεῖν (tassein) = to arrange and νόµος (nomos) = method) ...
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
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• Carl Linnaeus (ca. 1740) created a simple classification schema for organisms that is still used today
Carl Linnaeus(1707-1778)
Des Ritters Carl von Linné vollständiges Natursystem, 1778
Taxonomies
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
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• informal IS-A-Hierarchy: explicite hierarchy of classes, subclass relations are not strict(e.g. index of a library)
• formal IS-A-Hierarchy: explicite hierarchy of classes, subclass relations are strict
• formale instance: explicite class hierarchy, besides strict subclass relations also instance-of relations are allowed
Taxonomies
controlledVocabulary Thesauri
Terms/Glossary
informalis-a
formalis-a
formalInstance
Frames
ValueRestrictions
generallogical
Constraints
Disjunctness,Inversiveness,
Part-of…
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam
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Ontologies as Interpretation of Reality
various categories of animals from "a certain chinese encyclopedia" according to Jorge Luis Borges:
• Those that belong to the emperor• Embalmed ones• Those that are trained• Suckling pigs• Mermaids (or Sirens)• Fabulous ones• Stray dogs• Those that are included in this classification• Those that tremble as if they were mad• Innumerable ones• Those drawn with a very fine camel hair brush• Et cetera• Those that have just broken the flower vase• Those that, at a distance, resemble flies Jorge Luis Borges
(1899-1986)
Jorge Luis Borges: The Analytical Language of John Wilkins (1942)