Aligning Multiple Anatomical Ontologies through a Reference

Objective: To investigate the feasibility of deriving an indirect alignment between two ontologies from the two direct alignments of these ontologies to a reference ontology. The three anatomical ontologies under investigation are the Adult Mouse Anatomical Dictionary (MA), the NCI Thesaurus (NCI) and the Foundational Model of Anatomy (FMA). Methods: The direct alignment employs a combination of lexical and structural similarity. The indirect alignment simply derives mappings from direct alignments to the reference ontology. Each of the three ontologies is used, in turn, as the reference and evaluated against the other two ontologies. Results: Number of direct mappings identified: MA-NCI: 715, MA-FMA: 1,353 and NCI-FMA: 2,173. Number of indirect mappings identified through the reference: FMA: 703, NCI: 771 and MA: 741. Mappings specific to direct and indirect alignments are presented and discussed. Conclusions: This study confirms the feasibility of aligning two ontologies through a reference ontology. We also show that both the number of concepts and the number of concept names in the reference ontology are important parameters determining the suitability of an ontology to serve as a reference for deriving indirect mappings.