VocPub Profile - Specification
- URI
https://w3id.org/profile/vocpub/spec- Title
- VocPub Profile - Specification Document
- Definition
- This document specifies the VocPub Profile. It is to be used to inform people about the requirements that need to be met by data claiming to conform to the profile.
- Created
- 2020-06-14
- Modified
- 2022-04-24
- Creator
- Nicholas J. Car
- Contributor
- Simon J D Cox
- Publisher
- Australian Government Linked Data Working Group
- Further metadata
- This specification is part of the VocPub Profile. See that profile's main document for License & Rights information and other metadata not given here.
- Profile URI
https://w3id.org/profile/vocpub- License
- CC-BY 4.0
Abstract
This is the specification document of the VocPub profile of SKOS. It defines the requirements that data must satisfy to be considered conformant with this profile.
This specification is not to be used for testing conformance of RDF resoruces to this profile. That role belongs to the validation resource within this profile:
For the list of all resources within this profile, see the profile definition:
Namespaces
This document refers to elements of various ontologies by short codes using namespace prefixes. The prefixes and their corresponding namespaces' URIs are:
- dcterms
http://purl.org/dc/terms/- prof
http://www.w3.org/ns/dx/prof/- prov
http://www.w3.org/ns/prov#- sdo
https://schema.org/- skos
http://www.w3.org/2004/02/skos/core#- rdfs
http://www.w3.org/2000/01/rdf-schema#
1. Introduction
This profile defines a vocabulary as a controlled collection of defined terms that may or may not contain relationships between terms and relationships to terms in other vocabularies.
Many organisations use the Simple Knowledge Organization System Reference (SKOS)ref to represent vocabularies in a form that can be read by humans and consumed by machines; that is, in Semantic Web formref.
This document specifies a profile of SKOS and by profile, the definition of from the Profiles Vocabularyref is used. A profile is:
A specification that constrains, extends, combines, or provides guidance or explanation about the usage of other specifications.
Here, the other specification being profiled is SKOS.
In the next section, this document describes how SKOS's elements must be presented to make a vocabulary that conforms to this profile.
This specification's rules/requirements - are numbered and indicated in red text.
2. Elements & Requirements
2.1 Vocabulary
this profile identifies Semantic Web objects with URI-based persistent identifiers. For this reason:
2.1.1 Each vocabulary MUST be identified by a IRI
As per the SKOS Primerref, a document guiding the use of SKOS:
concepts usually come in carefully compiled vocabularies, such as thesauri or classification schemes. SKOS offers the means of representing such KOSs using the skos:ConceptScheme class.
For this reason, this profile requires that:
2.1.2 Each vocabulary MUST be presented as a single skos:ConceptScheme object
For ease of data management:
2.1.3 Each vocabulary MUST be presented in a single file which does not contain information other than that which is directly part of the vocabulary and the file is considered the point-of-truth
To ensure vocabularies can be catalogued effectively and governed:
2.1.4a Each vocabulary MUST have one and only one title indicated using the skos:prefLabel property that must be a text literal value
2.1.4b Each vocabulary MUST have one and only one definition value indicated using the skos:definition property that must be a text literal values
2.1.5 Each vocabulary MUST have one and only one created date and one and only one modified date indicated using the dcterms:created and dcterms:modified properties respectively that must be either an xsd:date, xsd:dateTime or xsd:dateTimeStamp literal value
2.1.6a Each vocabulary MUST have at least one creator, indicated using dcterms:creator property that must be a IRI value indicating an instances of sdo:Person, sdo:Organization or sdo:GovernmentOrganization
2.1.6b Each vocabulary MUST have at least one publisher, indicated using dcterms:publisher property that must be a IRI value indicating an instance of sdo:Person, sdo:Organization or sdo:GovernmentOrganization
To be able to link SKOS vocabularies to their non-vocabulary source information:
2.1.7 Provenance for a skos:ConceptScheme MUST be indicated by at least one of the following properties: dcterms:provenance, dcterms:source or prov:wasDerivedFrom.
If a vocabulary is based on another Semantic Web resource, such as an ontology or another vocabulary, prov:wasDerivedFrom should be used to indicate that resource's IRI. If the vocabulary is based on a resource that is identified by a IRI but which is not a Semantic Web resource, dcterms:source should be used to indicate the resource's IRI. If the vocabulary is based on something which cannot be identified by IRI, a statement about the thing should be given in a literal value indicated with the dcterms:provenance property. If the vocabulary is not based on any other resource or source of information, i.e. this vocabulary is its only expression, this should be communicated by use of the dcterms:provenance indicating the phrase "This vocabulary is expressed for the first time here".
To ensure that all the terms within a vocabulary are linked to the main vocabulary object, the skos:ConceptScheme:
2.1.8 All skos:Concept instances within a skos:ConceptScheme MUST be ordered in a single, term hierarchy using skos:broader and/or skos:narrower properties and which contains no cycles.
To unambiguously link the term hierarchy within a vocabulary to the vocabulary itself:
2.1.9 Each vocabulary's skos:ConceptScheme MUST link to at least one skos:Concept within the vocabulary as with the property skos:hasTopConcept
2.2 Collection
From the SKOS Primerref:
SKOS makes it possible to define meaningful groupings or "collections" of concepts
To ensure that skos:Collection instances are identifiable and their meaning isn't obscure or lost:
2.2.1a Each skos:Collection instance MUST have one and only one title indicated using the skos:prefLabel property that must be a text literal value
2.2.1b Each skos:Collection instance MUST have one and only one definition indicated using the skos:definition property that must be a text literal value
If a skos:Collection is derived from an existing resource:
2.2.2 Provenance for a skos:Collection SHOULD be indicated by at least one of the following properties: dcterms:provenance, dcterms:source or prov:wasDerivedFrom.
2.3 Concept
From the SKOS Primerref:
The fundamental element of the SKOS vocabulary is the concept. Concepts are the units of thought — ideas, meanings, or (categories of) objects and events—which underlie many knowledge organization systems
Vocabularies conforming to this profile must present at least one skos:Concept within the vocabulary file and, as per requirements in Section 2.1, at least once skos:Concept must be indicated as the top concept of the vocabulary.
To ensure that skos:Concept instances are identifiable and their meaning isn't obscure or lost:
2.3.1a Each skos:Concept instance MUST have one and only one title indicated using the skos:prefLabel property that must be a text literal value
2.3.1b Each skos:Concept instance MUST have one and only one definition indicated using the skos:definition property that must be a text literal value
To ensure that every skos:Concept is linked to the vocabulary that defines it:
2.3.2 Each skos:Concept in a vocabulary MAY indicate the vocabulary that defines it by use of the rdfs:isDefinedBy property indicating a skos:ConceptScheme instance
Note that the vocabulary that defines a skos:Concept does not have to be the vocabulary in the file being validated. This is to allow for skos:Concept instance reuse across multiple vocabularies.
Since a skos:Concept may be used in more than one vocabulary:
2.3.3 Each skos:Concept in a vocabulary MUST indicate that it appears within that vocabulary's hierarchy of terms by use of either or both skos:inScheme and skos:topConceptOf properties
If a skos:Concept is derived from an existing resource and that derivation is not already covered by source information for the vocabulary that it is within:
2.3.4 Provenance for a skos:Concept, if different from that of its containing skos:ConceptScheme, SHOULD be indicated by at least one of the following properties: dcterms:provenance, dcterms:source or prov:wasDerivedFrom.
2.3.5 Each skos:Concept in a vocabulary SHOULD indicate its permanent identifier as the value of a dcterms:identifier property. If the permanent identifier is a URI, the value may have the datatype ^^xsd:anyURI
2.4 Agent
To be consistent with other Semantic Web representations of agents, vocabularies' associated agents, creator & publisher must be certain typed RDF values:
2.4.1 Each agent associated with a vocabulary MUST be typed as an sdo:Person, sdo:Organization or sdo:GovernmentOrganization
To ensure human readability and association of agents with their non-Semantic Web (real world) form:
2.4.2 Each agent MUST indicate at least one name property with the sdo:name property that must be a text literal value
To ensure that agents are linked to non-Semantic Web forms of identification:
2.4.3 Each agent MUST indicate either a sdo:url (for organizations) or a sdo:email (for people) property with a URL or email value
3. References
- PROV
- Rob Atkinson; Nicholas J. Car (eds.). The Profiles Vocabulary. 18 December 2019. W3C Working Group Note. URL: https://www.w3.org/TR/dx-prof/
- SKOS
- Alistair Miles; Sean Bechhofer (eds.). SKOS Simple Knowledge Organization System Reference. 18 August 2009. W3C Recommendation. URL: https://www.w3.org/TR/skos-reference/
- SKOS Primer
- Antoine Isaac; Ed Summers (eds.). SKOS Simple Knowledge Organization System Primer. 18 August 2009. W3C Note. URL: https://www.w3.org/TR/skos-primer/
- Semantic Web
- World Wide Web Consortium. Semantic Web 2015. Web Page. URL: https://www.w3.org/standards/semanticweb/, accessed 2020-06-14