SNOMED CT’s Ontological Commitment

SNOMED CT is a clinical terminology that describes the meaning of terms by logical axioms. This requires an ontological commitment, i.e. precise agreements about the ontological nature of the entities referred to. We provide evidence that SNOMED implicitly supports at least three different kinds of commitments, viz. (i) independently existing entities, (ii) representational artifacts, and (iii) clinical situations. Our analysis shows how the truth-value of a sentence changes according to one of these perspectives. We argue that a clear understanding of to what kind of entities SNOMED CT concepts extend is crucial for the proper use and maintenance of SNOMED CT.