Ontologie et al. Begriffsdefinitionen im Kontext Wissensrepräsentation

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Ontologie et al.-Begriffsdefinitionen im KontextWissensrepräsentation

Peter Scheir

TU Graz & Know-Center

05/2006


© Know-Center / KMI

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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


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


Concept Map

Conceptual Graph

Topic Map

Ontologie

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Semantic Network / Semantisches Netz

Netzwerk von Begriffen


Typisierte Relationen

Beliebige Menge an Relationstypen

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Oft auf Quillian (1968) [5] zurückgeführt.

Spezielle Typen von Relationen:

is kind of (Kannarienvogel – Vogel)

is part of (Flügel – Vogel)

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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


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


Concept Map

Conceptual Graph

Topic Map

Ontologie

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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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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/

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Ontologie et al. Begriffsdefinitionen im Kontext Wissensrepräsentation