Investigating subsumption in SNOMED CT:
An exploration into large description logic-based
, Barry Smith
, Anand Kumar
, Anita Burgun
U.S. National Library of Medicine, National Institutes of Health, Bethesda, MD, USA
Institute for Formal Ontology and Medical Information Science, Saarland University, Germany
Department of Philosophy, University at Buffalo, New York, USA
EA 3888 Laboratoire d’Informatique Me
de Rennes I, France
Received 12 October 2004; received in revised form 10 December 2006; accepted 11 December 2006
Biomedical terminologies and ontologies are increas-
ingly takingadvantage of description logic (DL)-based
formalisms in representing knowledge. GALEN
SNOMED Clinical Terms
(in what follows SNOMED
were both developed in a native DL formalism.
Several other groups have worked at converting
existing terminologies into terminologies with a DL
Artiﬁcial Intelligence in Medicine (2007) 39, 183—195
Objective: Formalisms based on one or other ﬂavor of description logic (DL) are
sometimes put forward as helping to ensure that terminologies and controlled
vocabularies comply with sound ontological principles. The objective of this paper
is to study the degree to which one DL-based biomedical terminology (SNOMED CT)
does indeed comply with such principles.
Materials and methods: We deﬁned seven ontological principles (for example: each
class must have at least one parent, each class must differ from its parent) and
examined the properties of SNOMED CT classes with respect to these principles.
Results: Our major results are 31% of these classes have a single child; 27% have
multiple parents; 51% do not exhibit any differentiae between the description of the
parent and that of the child.
Conclusions: The applications of this principles to quality assurance for ontologies are
discussed and suggestions are made for dealing with the phenomenon of multiple
inheritance. The advantages and limitations of our approach are also discussed.
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