What is SKOS?

SKOS (Simple Knowledge Organization System) is a crucial component in FOLIO’s approach to representing and connecting multiple legal standards. It provides the vocabulary and structure needed for taxonomies and controlled vocabularies.

What is SKOS?

SKOS (Simple Knowledge Organization System) is a W3C recommendation designed for representing taxonomies, thesauri, classification schemes, subject heading systems, and other types of controlled vocabulary. It bridges the gap between complex formal ontology languages like OWL and the simple intuitive organization systems commonly used in practice.

SKOS provides a standard way to represent knowledge organization systems using RDF, making these valuable resources available to Semantic Web applications.

Key Features of SKOS in FOLIO

In FOLIO, SKOS plays several important roles:

  1. Preferred and Alternative Labels: SKOS allows FOLIO to specify the primary term for a concept (skos:prefLabel) as well as synonyms and alternative spellings (skos:altLabel). This is particularly valuable in legal systems where the same concept might be known by different names in different jurisdictions or practice areas.

  2. Hierarchical Relationships: SKOS provides properties like skos:broader and skos:narrower to establish hierarchical relationships between concepts. For example, “Tax Law” might be broader than “International Tax Law.”

  3. Associative Relationships: With skos:related, FOLIO can express connections between concepts that are associated but not in a hierarchical relationship.

  4. Notes and Documentation: SKOS includes properties for scope notes, definitions, examples, and historical notes, enhancing the value of FOLIO’s legal concept definitions.

  5. Concept Schemes: SKOS allows organizing concepts into schemes (skos:ConceptScheme), which helps FOLIO maintain multiple taxonomies for different aspects of legal information.

Example: SKOS in FOLIO

Here’s a simplified example of how a legal concept might be represented in FOLIO using SKOS:

@prefix folio: <https://folio.openlegalstandard.org/> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .

folio:R1ABd0796Ff01FF7573A211f a skos:Concept ;
    skos:prefLabel "Denmark"@en ;
    skos:altLabel "DK"@en ;
    skos:broader folio:R5E0c679BE29e3F86383A5bc ; # Europe
    skos:inScheme folio:JurisdictionScheme ;
    skos:note "Kingdom of Denmark, a Nordic country in Northern Europe."@en .

This example shows how FOLIO uses SKOS to represent Denmark as a jurisdiction, with its preferred label, alternative code, broader jurisdiction (Europe), and a descriptive note.

How SKOS Supports Multiple Standards

SKOS is particularly valuable for FOLIO’s mission of connecting multiple legal standards through:

  1. Mapping Properties: SKOS provides properties like skos:exactMatch, skos:closeMatch, skos:broadMatch, and skos:narrowMatch to establish connections between concepts in different schemes or standards.

  2. Multilingual Support: SKOS labels and documentation can be expressed in multiple languages, facilitating cross-border and multilingual legal work.

  3. Modular Organization: Different organizations can maintain their own SKOS concept schemes while establishing mappings to other schemes, supporting FOLIO’s federated approach.

The use of SKOS in FOLIO provides several key benefits:

  1. Simplified Knowledge Organization: Less complex than full OWL ontologies, making it more accessible for domain experts.
  2. Standardized Vocabulary Management: Common approach to representing labels, synonyms, and term relationships.
  3. Interoperability: Enables mapping between different terminologies and standards.
  4. Migration Paths: Provides a way to transition between different knowledge organization systems.

Real-World Applications

In FOLIO, SKOS helps address practical challenges like:

  • Mapping between different citation formats for the same case or statute
  • Connecting different practice area classification schemes
  • Reconciling terminology differences across jurisdictions
  • Supporting multilingual access to legal concepts

Explore the FOLIO Taxonomy

Browse the complete FOLIO taxonomy through our interactive browser.

Explore Taxonomy →

Further Reading

To continue exploring the technologies that power FOLIO: