Module 5

Vocabulary Reuse

Match concepts across vocabularies and track provenance correctly.

Why Reuse Vocabularies?

Building vocabularies from scratch is expensive. If an authoritative vocabulary already exists — from a standards body, government agency, or international registry — you can reuse it rather than duplicating work. Reuse creates semantic bridges between datasets that use different terms for the same concepts.

Reuse Patterns

Verbatim — use the existing vocabulary unchanged. Just reference its IRI.
Adoption — import some or all concepts into your vocabulary, retaining original IRIs and definitions.
Customise — make minor label/note changes; acknowledge modifications at concept and scheme level.
Matching — keep your vocabulary separate but declare relationships to concepts in the other.

SKOS Match Properties

When matching, you choose a relationship that reflects how similar the concepts are:

Property	Meaning	When to use
`skos:exactMatch`	Concepts are interchangeable in all contexts	High confidence equivalence across vocabularies
`skos:closeMatch`	Concepts are very similar but not identical	Strong resemblance with minor scope differences
`skos:broadMatch`	The other concept is more general	Your concept fits inside the external concept
`skos:narrowMatch`	The other concept is more specific	Your concept is a supertype of the external one
`skos:relatedMatch`	Loose thematic association across vocabularies	Related but not hierarchically linked

🔗 Exercise — Match concepts across vocabularies

Select one concept from each vocabulary, pick a match type, then click Add Match. Your matches will appear as Turtle below.

Our Vocabulary
Bushfire Risk Levels

Match Type

External Vocabulary
ISO 22324 Warning Colours

matches.ttl — Turtle output

Provenance: Where did this concept come from?

When you adopt or customise concepts from another vocabulary, you must record where they came from using W3C PROV-O properties:

provenance.ttl

@prefix prov:    <http://www.w3.org/ns/prov#> .
@prefix dcterms: <http://purl.org/dc/terms/> .
@prefix vocdm:   <https://linked.data.gov.au/def/vocdermods/> .

# The derived concept scheme
<https://example.org/risk/BushfireRiskLevels>
    prov:wasDerivedFrom  <https://iso.org/vocab/22324> ;
    dcterms:source       <https://iso.org/vocab/22324> ;
    # Derivation mode: relabelling | subsetting | extension | mix
    vocdm:derivationMode vocdm:extension .

Language Tags

When supporting multiple languages or regional variants, declare the primary language on the ConceptScheme and use BCP 47 tags on labels. Keep the plain @en tag alongside regional variants for broad compatibility:

multilingual.ttl

<https://example.org/risk/High>
    skos:prefLabel  "High Risk"@en ;
    skos:prefLabel  "High Risk"@en-AU ;
    skos:altLabel   "Hohes Risiko"@de ;
    skos:altLabel   "Wildfires"@en-GB .

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