OWL Standard
The OWL Standard is an ontology description language standard designed for sharing ontologies on the Web.
- AKA: OWL, Ontology Web Language, OWL Web Ontology Language.
- Context:
- It was originally designed to support automated Web Services.
- It is based on XML and RDF.
- It is based on Description Logic.
- It is associated to OWL Time.
- It can be used to define an OWL-based Ontology.
- It subscribes to RDFS. It does not subscribe to XML Schema.
- It can be: an OWL Lite, OWL DL, or OWL Full.
- Example(s):
- OWL1 Standard.
- http://www.linguistics-ontology.org/gold.html
- An ontology of known metabolic pathways can be found at [1].
- OWL 2 Web Ontology Language.
- …
- OWL1 Standard.
- Counter-Example(s):
- See: XML Standard, RDF Standard, Ontology Definition MetaModel.
References
- TBD
- "OWL-Lite is based on the SHIF (D) and OWL-DL is based on the SHOIN (D) description logics. There are a number of differences between these two flavors. Most important for us were value restrictions and exact cardinality restrictions in OWL-DL. Whereas OWL-Lite allows only zero, one-to-one, and one-to-many relations, In OWL-DL we can specify an exact range of allowed relationships for a class. We can say, for example, that a student must have at least 3, but no more than 5 advisors on his committee. Just like OWL-Lite, OWL-DL is fully decidable."
2007
- (Obitko, 2007) ⇒ Marek Obitko. (2007). “Translations Between Ontologies in Multi-agent Systems - Ontology Operations].” PhD Thesis, Czech Technical University http://www.obitko.com/tutorials/ontologies-semantic-web/web-ontology-language-owl.html
- The Web Ontology Language OWL extends RDF and RDFS. Its primary aim is to bring the expressive and reasoning power of description logic to the semantic web. Unfortunately, not everything from RDF can be expressed in DL. For example, the classes of classes are not permitted in the (chosen) DL, and some of the triple expressions would have no sense in DL. That is why OWL can be only syntactic extension of RDF/RDFS (note that RDFS is both syntactic and semantic extension of RDF). To partially overcome this problem, and also to allow layering within OWL, three species of OWL are defined.
OWL Lite can be used to express taxonomy and simple constraints, such as 0 and 1 cardinality. It is the simplest OWL language and corresponds to description logic SHIF. OWL DL supports maximum expressiveness while retaining computational completeness and decidability. The DL in the name shows that it is intended to support description logic capabilities. OWL DL corresponds to description logic SHOIN. OWL Full has no expressiveness constraints, but also does not guarantee any computational properties. It is formed by the full OWL vocabulary, but does not no impose any syntactic constrains, so that the full syntactic freedom of RDF can be used.
These three languages are layered in a sense that every legal OWL Lite ontology is a legal OWL DL ontology, every legal OWL DL ontology is a legal OWL Full ontology, every valid OWL Lite conclusion is a valid OWL DL conclusion, and every valid OWL DLconclusion a valid OWL Full conclusion. The inverses of these relations generally do not hold. Also, every OWL ontology is a valid RDF document (i.e., DL expressions are mapped to triples), but not all RDF documents are valid OWL Lite or OWL DL documents.
- The Web Ontology Language OWL extends RDF and RDFS. Its primary aim is to bring the expressive and reasoning power of description logic to the semantic web. Unfortunately, not everything from RDF can be expressed in DL. For example, the classes of classes are not permitted in the (chosen) DL, and some of the triple expressions would have no sense in DL. That is why OWL can be only syntactic extension of RDF/RDFS (note that RDFS is both syntactic and semantic extension of RDF). To partially overcome this problem, and also to allow layering within OWL, three species of OWL are defined.
2009a
- http://en.wikipedia.org/wiki/Web_Ontology_Language
- The Web Ontology Language (OWL) is a family of knowledge representation languages for authoring ontologies, and is endorsed by the World Wide Web Consortium. This family of languages is based on two (largely, but not entirely, compatible) semantics: OWL DL and OWL Lite semantics are based on Description Logic, which have attractive and well-understood computational properties, while OWL Full uses a semantic model intended to provide compatibility with RDF Schema. OWL ontologies are most commonly serialized using RDF/XML syntax. OWL is considered one of the fundamental technologies underpinning the Semantic Web, and has attracted both academic and commercial interest.
2009b
- http://www.w3.org/TR/owl2-overview/ OWL 2 Web Ontology Language, Document Overview
- The OWL 2 Web Ontology Language, informally OWL 2, is an ontology language for the Semantic Web with formally defined meaning. OWL 2 ontologies provide classes, properties, individuals, and data values and are stored as Semantic Web documents. OWL 2 ontologies can be used along with information written in RDF, and OWL 2 ontologies themselves are primarily exchanged as RDF documents.
- … Ontologies are formalized vocabularies of terms, often covering a specific domain and shared by a community of users. They specify the definitions of terms by describing their relationships with other terms in the ontology.
- … OWL 2 is an extension and revision of the OWL Web Ontology Language developed by the W3C Web Ontology Working Group and published in 2004 (referred to hereafter as “OWL 1”). OWL 2 is being developed (and this document was written) by a follow-on group, the W3C OWL Working Group. Like OWL 1, OWL 2 is designed to facilitate ontology development and sharing via the Web, with the ultimate goal of making Web content more accessible to machines.