IKOS
IPTC Knowledge Organisation System - IKOS
IPTC is the provider of about 200 controlled vocabularies or taxonomies holding thousands of concepts to be used with news - the IPTC NewsCodes.
For making these vocabularies publicly available and for their IPTC-internal management an IPTC Knowledge Organisation System (IKOS) was created, its key items are:
- The basic data model follows IPTC NewsML-G2 Concepts and Knowledge Items
- It adopts as much as possible from the W3C Simple Knowledge Organisation System - SKOS
- It adds what is required by specific needs for IPTC concepts and vocabularies
IPTC implements this design by different formats building on common semantics - find details in the table below: (You can open this table as stand-alone page)
- Starting point is the expression as Concept Item and Knowledge Items/Concept Scheme defined by NewsML-G2 (first column)
- plus a definition of the semantics of the properties (second column) - Mapping these NewsML-G2 properties to a SKOS term and if none is available to an IKOS term (third column) which can be used in the RDF context.
- A native-JSON format for properties and their values (fourth column)
- Expressing properties and their values as JSON-LD nodes. This builds on a JSON-LD @context object mapping in the SKOS and IKOS terms (fifth column)
- All terms in a row defined for NewsML-G2, SKOS/IKOS and the native-JSON share the same definition of the second column.
Technical details
The NewsML-G2 specifications for expressing Concept Items and Knowledge Items by XML can be found in the NewsML-G2 section of this Developer Site.
Technical definitions for expressing Concepts and Concept Schemes/Vocabularies using SKOS and IKOS by JSON are available in the Github repository https://github.com/iptc/json-for-concepts-vocabularies:
- For a native-JSON format: the IKOS JSON Schemas - with a sample
- For JSON-LD: an IKOS @context as file - with a sample