Ontology Alignment Evaluation Initiative - OAEI-2010 Campaign

A note about handling SKOS

Ontology matchers tend to require ontologies to be matched (this is the least). Yet SKOS thesauri are not really ontologies. There are a few options for doing this.

Direct handling of SKOS

Since version 4.1 (or the current version under svn), the Alignment API is able to handle SKOS thesauri thanks to its Ontology wrapper and the SKOS API.

Translation from SKOS to OWL

People may want to translate SKOS thesauri into OWL ontologies. We are aware of at least two ways to achieve this.

Use the converted ontologies provided for the food, environment and library test sets. According to the description provided by Antoine Issac (older version here), they obey the following rules:

• instances of skos:Concept are converted into instances of owl:Class;
• skos:prefLabel, skos:altLabel and skos:hiddenLabel statements are converted to rdfs:label statements, which removes the subtle distinctions that exist between these different properties (for instance, altLabels are often not synonyms at all);
• various kind of skos:notes are converted to rdfs:comments;
• skos:broader statements are converted into rdfs:subClassOf statements;
• skos:related statements are converted into rdfs:seeAlso statements.

Use the tool developed by Miklos Nagy for the same purpose. It uses the following set of rules (see also Miklos provided short description):

• skos:Concept -> owl:Class
• skos:prefLabel -> rdfs:label
• skos:altLabel -> rdfs:label
• skos:broader -> rdfs:subClassOf
• skos:definition -> rdfs:comment
• skos:scopeNote -> rdfs:comment

Antoine also plans to evaluate alignments that use OWL properties as mapping links. The following interpretations will be made of OWL data sent back by participants:

• instances of owl:Class will be interpreted as instances of skos:Concept;
• owl:equivalentClass statements will be interpreted as skos:exactMatch statements;
• if participants match the original concepts (as instances of skos:Concept and not owl:Class) using owl:sameAs, these statements will also be interpreted as skos:exactMatchs;
• rdfs:subClassOf statements will be interpreted as skos:broaderMatch statements;
• rdfs:seeAlso statements will be interpreted as stitch:relatedMatch statements;