title: The Pitfalls of Thesaurus Ontologization - the Case of the NCI Thesaurus.
abstract: Thesauri that are "ontologized" into OWL-DL semantics are highly amenable to modeling errors resulting from falsely interpreting existential restrictions. We investigated the OWL-DL representation of the NCI Thesaurus (NCIT) in order to assess the correctness of existential restrictions. A random sample of 354 axioms using the someValuesFrom operator was taken. According to a rating performed by two domain experts, roughly half of these examples, and in consequence more than 76,000 axioms in the OWL-DL version, make incorrect assertions if interpreted according to description logics semantics. These axioms therefore constitute a huge source for unintended models, rendering most logic-based reasoning unreliable. After identifying typical error patterns we discuss some possible improvements. Our recommendation is to either amend the problematic axioms in the OWL-DL formalization or to consider some less strict representational format.
authors.affiliation: Medical Informatics Group, University Medical Center Freiburg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schulz
authors.forename: Daniel
authors.initials: D
authors.lastname: Schober
authors.forename: Ilinca
authors.initials: I
authors.lastname: Tudose
authors.forename: Holger
authors.initials: H
authors.lastname: Stenzhorn
mesh_terms: D006801:Humans; D008128:Logic; D008962:Models, Theoretical; D012660:Semantics; D018875:Vocabulary, Controlled