Tech TalkBIBFRAME Working Group

15 September 2015

Allison Jai O’Dell, Metadata Librarian | AJODELL@ufl.edu | (352) 273-2667 | 404 Library East

Ontologies“In computer science and information science, an ontology is a formal naming and definition of the types, properties, and interrelationships of the entities that really or fundamentally exist for a particular domain of discourse. It is thus a practical application of philosophical ontology, with a taxonomy.” – Wikipedia

Ontology Components

Individuals: instances or objects

Classes: sets, collections, concepts, types of objects, or kinds of things

Attributes: aspects, properties, features, characteristics, or parameters that objects (and classes) can have

Relations: ways in which classes and individuals can be related to one another

Example: RDA Registry http://www.rdaregistry.info/

Ontology Languages“An ontology language is a formal language used to encode the ontology. ”

– Wikipedia

RDF Schema (RDFS)

• Classes• 2.1 rdfs:Resource• 2.2 rdfs:Class• 2.3 rdfs:Literal• 2.4 rdfs:Datatype• 2.5 rdf:langString• 2.6 rdf:HTML• 2.7 rdf:XMLLiteral• 2.8 rdf:Property

• Properties• 3.1 rdfs:range• 3.2 rdfs:domain• 3.3 rdf:type• 3.4 rdfs:subClassOf• 3.5 rdfs:subPropertyOf• 3.6 rdfs:label• 3.7 rdfs:comment

“A set of classes with certain properties using the RDF extensibleknowledge representation data model, providing basic elements for the description of ontologies, otherwise called RDF vocabularies, intended to structure RDF resources.” – Wikipedia

http://www.w3.org/TR/rdf-schema/

Web Ontology Language (OWL)

“The OWL Web Ontology Language is designed for use by applications that need to process the content of information instead of just presenting information to humans. OWL facilitates greater machine interpretability of Web content than that supported by XML, RDF, and RDF Schema (RDF-S) by providing additional vocabulary along with a formal semantics. OWL has three increasingly-expressive sublanguages: OWL Lite, OWL DL, and OWL Full.” – W3C, OWL Features

http://www.w3.org/TR/owl-features/

Ontology languages are used to write ontologies. Such as:

Simple Knowledge Organization System (SKOS)

“W3C recommendation designed for representation of thesauri, classification schemes, taxonomies, subject-heading systems, or any other type of structured controlled vocabulary. SKOS is part of the Semantic Web family of standards built upon RDF and RDFS, and its main objective is to enable easy publication and use of such vocabularies as linked data.” – Wikipedia

SKOS = the Linked Data ontology for encoding library thesauri

http://www.w3.org/2004/02/skos/

SKOS Elements

ConceptsLabels &

NotationDocumentation

Semantic

Relations

Mapping

PropertiesCollections

Concept prefLabel note broader broadMatch Collection

ConceptScheme altLabel changeNote narrower narrowMatch orderedCollection

inScheme hiddenLabel definition related relatedMatch member

hasTopConcept notation editorialNote broaderTransitive closeMatch memberList

topConceptOf example narrowerTransitive exactMatch

historyNote semanticRelation mappingRelation

scopeNote

SKOS applies principles and relationships from library thesaurus design,

and adds extras that become possible in Web and Linked Data environments.