Alignment of Multiple Ontologies of Anatomy: Deriving Indirect Mappings from Direct Mappings to a Reference

OBJECTIVE To investigate the indirect alignment of two anatomical ontologies through a reference ontology and to compare it to direct alignment between these two ontologies. The ontologies under investigation are the Adult Mouse Anatomical Dictionary (MA) and the NCI Thesaurus (NCI). The Foundational Model of Anatomy serves as reference ontology. 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. RESULTS The indirect MA-NCI alignment yielded 703 mappings and the direct alignment 715, 654 of which are common to both. The mappings specific to one approach were analyzed. CONCLUSIONS When a reference ontology exists, indirect alignment of multiple ontologies through a reference represents a valid, cost-effective alternative to pairwise alignment.