title: Exploiting UMLS semantics for checking semantic consistency among UMLS concepts.
abstract: OBJECTIVE
  To quantify semantic inconsistency in UMLS concepts from the perspective of their hierarchical relations and to show through examples how semantically-inconsistent concepts can help reveal erroneous synonymy relations.
  
  
  METHODS
  Inconsistency is defined in reference to concepts from the UMLS Metathesaurus. Consistency is evaluated by comparing the semantic groups of the two concepts in each pair of hierarchically-related concepts. A limited number of inconsistent concepts was inspected manually.
  
  
  RESULTS
  81,512 concepts are inconsistent due to the differences in semantic groups between a concept and its parent. Four examples of wrong synonymy are presented.
  
  
  CONCLUSIONS
  A vast majority of inconsistent hierarchical relations are not indicative of any errors. We discovered an interesting semantic pattern along hierarchies, which seems associated with wrong synonymy.
authors.affiliation: Faculty of Engineering and Natural Sciences, Sabancı University, Turkey.
authors.forename: Halit
authors.initials: H
authors.lastname: Erdogan
authors.forename: Esra
authors.initials: E
authors.lastname: Erdem
authors.forename: Olivier
authors.initials: O
authors.lastname: Bodenreider
mesh_terms: D001185:Artificial Intelligence; D057225:Data Mining / Q000379:methods*; D009323:Natural Language Processing; D012660:Semantics; D009626:Terminology as Topic; D014421:Turkey; D017432:Unified Medical Language System