CDIF SKOS profile

CDIF SKOS profile#

A skos:ConceptScheme: a set of concepts that define the possible values for a categorical variable. The scheme can define a hierarchy of values from general to more specific. This hierarchy is represented using the skos:broader relationship linking more specific concepts to subsuming more general concepts. If a hierarchy is defined in the scheme the top concept(s), i.e. those that do not have any skos:broader associations, must be identified using the skos:hasTopConcept property on the skos:ConceptScheme.

skos:Concept: represent the possible values for a categorical variable. In the RDF implementation of a skos:ConceptScheme, these are the requirements for each concept:

  • must specify rdf:type skos:Concept.

  • must have a globally unique, resolvable identifier.

  • must have a skos:inScheme relationship to the containing skos:ConceptScheme.

  • must have at least one skos:prefLabel, but may have multiples as these are language specific (SKOS does not permit more than one skos:prefLabel per language-locale).

  • must provide a definition of the concept with skos:definition, also in language-specific form.

  • must use the skos:broader relationship to indicate its parent in the hierarchy if the concept scheme is hierarchical

  • a unique (in the scope of the vocabulary) skos:Notation must be provided if skos:Notation is used to denote the skos:Concept in data instances. This is not necessary if unique URIs are used instead of a skos:Notation in data instances. The convention must be defined in a vocabulary profile. skos:Notation values are commonly short strings or abbreviations that are easier for users to interpret than the concept identifier.

  • Other labels may be provided using skos:altLabel, also in language-specific form.

  • skos:narrower relationships (inverse of skos:broader) can be provided, supporting navigation both up and down the concept hierarchy.

This use of SKOS materially aligns with that described in the document ‘Modelling of Eurostat’s Statistical Classifications in ShowVoc’ for classification items.