Ontology

From semanticweb.org

Ontologies are considered one of the pillars of the Semantic Web, although they do not have a universally accepted definition. A (Semantic Web) vocabulary can be considered as a special form of (usually light-weight) ontology, or sometimes also merely as a collection of URIs with an (usually informally) described meaning.

Ontologies on semanticweb.org are usually assumed to be accompanied by some document in a formal ontology language, though some ontologies do not use standardised formats for that purpose. A list of documents that are considered ontologies in this wiki is given below.

Contents 1 Definitions 2 Ontologies on semanticweb.org 3 Microformats in RDF 4 Further examples

[edit] Definitions

There have been several definitions of what an ontology is.

• An ontology is a formal specification of a shared conceptualization (Tom Gruber, see [1]). Many authors cite this definition.
• The main thread of ontology in the philosophical sense is the study of entities and their relations. The question ontology asks is: What kinds of things exist or can exist in the world, and what manner of relations can those things have to each other? Ontology is less concerned with what is than with what is possible. Clay Shirky in his critical entry Ontology is overrated [2]. He says this is the first meaning. AI people took the word and rather define it as "an explicit specification of a conceptualization.", pointing to Gruber.
• ...

(If you add another one, please always cite the source as well)

[edit] Ontologies on semanticweb.org

The following vocabularies and ontologies are currently described on semanticweb.org, ordered by the occurrence on the web as estimated by Swoogle. See also the UMBC Top 100 of common namespaces. As the revision dates given here indicate, some of the below data may require update: feel free to contribute!

	Language	Swoogle hits	Revised
Dublin Core	RDF	13643371,364,337	245403728 October 2006
FOAF	OWL DL	619538619,538	245357927 July 2005
MetaVocab	RDF	441790441,790	245232216 February 2002
Basic Geo Vocabulary	RDF Schema	248130248,130	24537681 February 2006
BIO	RDF	220228220,228	24530705 March 2004
RSS 1.0	RDF Schema	201786201,786	24518856 December 2000
VCard RDF	RDF	181962181,962	245196322 February 2001
Creative Commons metadata	RDF Schema	112216112,216
WOT	OWL DL	9729297,292	245305923 February 2004
SIOC	OWL DL	4291142,911	245456811 April 2008
Goodrelations	OWL DL	15541,554	24549575 May 2009
DOAP	RDF Schema	14421,442	24536805 November 2005
Provenance Vocabulary	OWL DL	11	245506925 August 2009
Argumentation Ontology	OWL 2	11	245399213 September 2006
OpenGUID	RDF Schema	11	245473424 September 2008

[edit] Microformats in RDF

• hCard
• hCalendar
• adr
• rel-tag
• rel-license
• hReview
• hAtom
• xfn
• geo
• hResume
• hRecipe

[edit] Further examples

• Open Biomedical Ontologies
• Ontology Design Patterns
• Semantic Web for Earth and Environmental Terminology (NASA)
• LKIF Core Ontology of Basic Legal Concepts
• OpenGALEN Medical Ontology
• Stanford Library of Ontologies
• An Ontology for Engineering Mathematics(paper)
• SUMO
• WordNet
• DOLCE Homepage
• DOLCE+Descriptions and Situations OWL ontologies
• Quantum Mechanics Ontology
• Engineering Mathematics Ontologies
• DAML List of Ontologies (outdated)
• SchemaWeb (List of Ontologies)
• Ontology for Long Term Ecological and Socioecological research
• Ontology Online
• Finance ontology Ontology on securities handling.