K KurrawongAI Training
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Module 2

Introduction to Vocabularies

SKOS — the W3C standard for publishing controlled vocabularies as linked data.

What is a Vocabulary?

A vocabulary provides a standardised set of terms with unique identifiers — so that two systems referring to the same thing, even where they have different labels or terms, may treat these things as equivalent.

  • Human understanding — labels and definitions in plain language
  • Machine processing — unique IRIs that computers can match unambiguously

Types of Vocabularies

  • Glossary — concepts with labels and definitions only
  • Taxonomy — adds broader/narrower hierarchy
  • Thesaurus — taxonomy + non-hierarchical associations + synonym control
Glossary
Fire RiskFire Danger

The chance of a bushfire and its likely severity.

Grassfire

An unplanned fire burning in grassland.

Flat list — labels and definitions, no links between concepts.

Taxonomy
Fire Risk
↳High Risk
↳Low Risk

Adds hierarchy — broader / narrower nesting.

Thesaurus
Fire Risk
↳High RiskExtreme
┄ related ┄▸Total Fire Ban

Hierarchy plus non-hierarchical related links and synonym control.

solid nodes are skos:prefLabels; dashed chips are skos:altLabels (alternative labels for the same concept).

SKOS Core Properties
skos:ConceptSchemeThe container for your vocabulary — holds metadata like title, creator, and links to all top concepts.
skos:ConceptA single term in your vocabulary. Must have an IRI, a prefLabel, a definition, and link to the vocabulary with skos:inScheme.
skos:prefLabelThe preferred human-readable label.
skos:altLabelAlternative labels — synonyms, acronyms, or superseded terms. Multiple allowed.
skos:definitionA textual definition or description of a skos:Concept. Required by VocPub. Should be self-contained.
skos:broaderPoints to a more general concept. Enables hierarchy navigation and automates search expansion.
skos:narrowerPoints to a more specific concept. Inverse property of skos:broader.
skos:relatedA non-hierarchical association between two concepts in the same scheme.
skos:topConceptOfDeclares this concept is a top of a ConceptScheme.
skos:scopeNoteClarifies what is included or excluded from a concept's scope.

Annotated Turtle

Hover over each coloured token to see what it does.

Exercise — Hover the tokens to learn each part

Hover over each coloured token to see what it does.

bushfire-risks.ttl
@prefix risk: <https://example.org/risk/> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .
@prefix dcterms: <http://purl.org/dc/terms/> .

risk:BushfireRiskLevels
    a skos:ConceptScheme ;
    dcterms:title   "Australian Bushfire Risk Levels"@en ;
    skos:hasTopConcept  risk:Extreme, risk:High, risk:Medium, risk:Low .

risk:High
    a skos:Concept ;
    skos:prefLabel   "High Risk"@en ;
    skos:definition "Conditions likely to result in significant, fast-moving fire."@en ;
    skos:altLabel   "High"@en ;
    skos:narrower    risk:HighGrass, risk:HighForest ;
    skos:topConceptOf  risk:BushfireRiskLevels .
Hover a coloured term above to see its explanation.

Make a simple change to a Turtle file

Now edit the same concept yourself. Three predicates — skos:altLabel, skos:scopeNote, and skos:related — have been added with empty values. Place each value where it belongs: a synonym, a scope note, and a link to a related concept.

Exercise — Fill in the empty predicates

Pick a value below, then click the predicate it belongs to. The three predicates are empty — place each value where it fits. Click Check Answer to see how you did.

bushfire-risks.ttl
@prefix risk: <https://example.org/risk/> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .

risk:High
    a skos:Concept ;
    skos:prefLabel  "High Risk"@en ;
    skos:definition "Conditions likely to result in significant, fast-moving fire."@en ;
    skos:altLabel   ;
    skos:scopeNote  ;
    skos:related    .
Values — pick one, then click its predicate

Hierarchy: broader and narrower

SKOS hierarchies follow the all-some rule: if Grassfire is narrower than Bushfire, then all grassfires are bushfires, and only some bushfires are grassfires.

Exercise — Browse the concept hierarchy

Click any concept to see its SKOS properties.

VocPub Profile
The VocPub profile requires every concept to have skos:prefLabel, skos:definition, and membership in a skos:ConceptScheme.
Module 1