Ontologie et al.-
Begriffsdefinitionen im Kontext
Wissensrepräsentation
Peter Scheir
TU Graz & Know-Center
http://www.know-center.at/swat
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Überblick
Einführung - Ontologie
Taxonomie
Thesaurus
Semantisches Netz / Assoziatives Netz
Concept Map
Conceptual Graph
Topic Map
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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 the
universe of discourse with human-readable text
describing what the names mean, and formal axioms
that 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
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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
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Überblick
Ontologie
Taxonomie
Thesaurus
Semantisches Netz / Assoziatives Netz
Concept Map
Conceptual Graph
Topic Map
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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
21
Ontologie
http://www.know-center.at/swat
05/2006 © Know-Center / KMI

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 the
universe of discourse with human-readable text
describing what the names mean, and formal axioms
that constrain the interpretation and well-formed use of
these terms. Formally, an ontology is the statement of a
logical theory
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Ontologie (Gruber) [1]
Ontologies are often equated with taxonomic
hierarchies of classes, but class definitions, and
the subsumption relation, but ontologies need
not be limited to these forms. … To specify a
conceptualization one needs to state axioms
that do constrain the possible interpretations
for 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 natural
language.
A formal ontology is specified by a collection
of names for concept and relation types
organized 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-
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readable and machine-processable.
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Diskussionsgrundlage
Begriff Formale Informale
Ontologie Ontologie
Taxonomie ~
Thesaurus
Semantisches Netz ~
Assoziatives Netz ~ ~
Concept Map
Conceptual Graph
Topic Map
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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/
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