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Ontologie et al.-Begriffsdefinitionen im KontextWissensrepräsentation
Peter Scheir
TU Graz & Know-Center
05/2006
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Überblick
Einführung - Ontologie
Taxonomie
Thesaurus
Semantisches Netz / Assoziatives Netz
Concept Map
Conceptual Graph
Topic Map
Ontologie
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Ontologie (Gruber) [1]
explicit specification of a conceptualization
conceptualization is an abstract, simplified view of the world that we wish to represent for some purpose
Definitions associate the names of entities in theuniverse of discourse with human-readable textdescribing what the names mean, and formal axiomsthat constrain the interpretation and well-formed use of these terms. Formally, an ontology is the statement of a logical theory
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Taxonomie
Einteilung von Dingen in Gruppen
Kontrolliertes Vokabular
Kann hierarchische sein
Z.B. Einteilung von Tierarten in ein hierarchischem System
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Taxonomie
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Thesaurus
Wortnetz
Kontrolliertes Vokabular
Begriffe mit typisierten Relationen
Definierte Menge an Relationen:
Äquivalenz
Assoziation
Hierarchische Relationen
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Thesaurus
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Überblick
Ontologie
Taxonomie
Thesaurus
Semantisches Netz / Assoziatives Netz
Concept Map
Conceptual Graph
Topic Map
Ontologie
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Semantic Network / Semantisches Netz
Netzwerk von Begriffen
Kontrolliertes Vokabular
Typisierte Relationen
Beliebige Menge an Relationstypen
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Semantic Network / Semantisches Netz
Oft auf Quillian (1968) [5] zurückgeführt.
Spezielle Typen von Relationen:
is kind of (Kannarienvogel – Vogel)
is part of (Flügel – Vogel)
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Semantic Network / Semantisches Netz
Graphische Sprache
Knoten stehen für Konzept
Kanten für Beziehung zwischen verbunden Konzepten
Semantik von Knoten und Kanten nicht eindeutig interpretierbar
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Assoziatives Netzwerk
Netzwerk von Dingen
Kanten stehen für Assoziation zwischen Dinge
Können benannt und/oder gewichtet sein
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Concept Map
Graphisches Werkzeug für:
Wissensdarstellung
Brainstorming
Wissensorganisation
Konzepte und Verbindungen
Kein zentraler Begriff (wie in Mindmap)
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Concept Map
05/2006
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Überblick
Ontologie
Taxonomie
Thesaurus
Semantisches Netz / Assoziatives Netz
Concept Map
Conceptual Graph
Topic Map
Ontologie
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Conceptual Graphs
1984 - John Sowa
Concept
Conceptual Relation
Concept Types
Relation Types
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Conceptual Graphs [6] [7]
(Betw [Rock] [Place *x] [Person]) (Attr ?x [Hard])
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Topic map
1999 - ISO Standard (ISO 13250)
Erstellung von Wissensstrukturen
Verbindung der Struktur mit Information
Topics (Types, Names)
Assoziationen (Types, Roles)
Occurences (Roles)
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XML Topic Maps
2001 - XML Topic Maps (XTM) 1.0
XML Standard zur Serialisierung von Topic Maps
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Topic map [3]
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Überblick
Ontologie
Taxonomie
Thesaurus
Semantisches Netz / Assoziatives Netz
Concept Map
Conceptual Graph
Topic Map
Ontologie
05/2006
http://www.know-center.at/swat
© Know-Center / KMI
22
Ontologie (Gruber) [1]
explicit specification of a conceptualization
conceptualization is an abstract, simplified view of the world that we wish to represent for some purpose
Definitions associate the names of entities in theuniverse of discourse with human-readable textdescribing what the names mean, and formal axiomsthat constrain the interpretation and well-formed use of these terms. Formally, an ontology is the statement of a logical theory
05/2006
http://www.know-center.at/swat
© Know-Center / KMI
23
Ontologie (Gruber) [1]
Ontologies are often equated with taxonomichierarchies of classes, but class definitions, and the subsumption relation, but ontologies neednot be limited to these forms. … To specify a conceptualization one needs to state axiomsthat do constrain the possible interpretationsfor the defined terms.
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Ontologie (Guarino) [2]
An ontology is a logical theory accounting for the intended meaning of a formal vocabulary, i.e. its ontological commitment to a particular conceptualization of the world. The intended models of a logical language using such a vocabulary are constrained by its ontological commitment. An ontology indirectly reflects this commitment (and the underlying conceptualization) by approximating these intended models.
an ontology is language-dependent
a conceptualization is language-independent
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Ontologie (Sowa) [8]
An informal ontology may be specified by a catalog of types that are either undefined or defined only by statements in a naturallanguage.
A formal ontology is specified by a collectionof names for concept and relation typesorganized in a partial ordering by the type-subtype relation.
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Ontologie (Obrst) [4]
With respect to definitions of ontologies, I hope to send a portion of a briefing I made at the Army Knowledge Management Conference in Ft. Lauderdale late Aug/early Sept of 2004, that takes you through the ontology spectrum, from taxonomy (weak and strong) to thesaurus (a strong term taxonomy+) to conceptual model (weak ontology) to logical theory (strong ontology).
The first is unstandardized, the second and third each has a set of standards associated with them, the third and fourth have multiple representation languages supporting them, and the last has some logic behind the representation language, typically ranging from a description logic (OWL) to first-order logic (KIF, Common Logic) to a higher order logic.
A logical theory is a formal ontology. The others range from informal to semi-formal. Other informal ontologies can be natural language sentences in a document. The key point about formal ontologies (logical theories) is that they are machine-interpretable, i.e., semantically interpretable by machine. The others are not, are only interpretable by human beings, though they may be machine-readable and machine-processable.
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Diskussionsgrundlage
Conceptual Graph
Topic Map
Concept Map
~~Assoziatives Netz
~Semantisches Netz
Thesaurus
~Taxonomie
InformaleOntologie
FormaleOntologie
Begriff
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Referenzen
[1] Thomas Gruber, Toward Principles for the Design of Ontologies Used for Knowledge Sharing (1993)
[2] Nicola Guarino, Formal Ontology and Information Systems (1998)
[3] Steve Pepper, The TAO of Topic Maps, http://www.ontopia.net/topicmaps/materials/tao.html
[4] Leo Obrst, Re: [ontolog-forum] Updating the Ontolog Charter ... definitionsandUBL(2005), http://ontolog.cim3.net/forum//ontolog-forum/2005-03/msg00005.html#nid04
[5] Ross Quillian, Semantic Memory (1968)
[6] John Sowa, Conceptual Graph Examples, http://www.jfsowa.com/cg/cgexampw.htm
[7] John Sowa, Conceptual Graph Standard, http://www.jfsowa.com/cg/cgstand.htm
[8] John Sowa, Ontology, http://www.jfsowa.com/ontology/