Large terminology systems with complex intertwined structure can be hard to navigate and get acquainted with.
Results for UMLS are best since it is the largest terminology with nearly 10 million terms which include GO, MeSH and OBO terms.
The goal is to transform a large terminology-based ontology into one with the ability to support reasoning applications.
Computerised mapping systems could significantly reduce human effort, especially for mapping between large terminologies.
Letrilliart et al concluded that when software incorporates large terminologies, physicians will use it only if they are special trained and rewarded [ 13].
In order to increase human readability in large terminologies, concepts can be grouped by structure nodes, and variants can be centrally stored in dictionaries.
Indeed, given the low rate of coding agreement reported when using large terminologies, e.g. [ 19], which at best represent only a fraction of SNOMED CT regarding their size and complexity, it is expected that large-scale ontology-driven coding tasks will require computer tools to assist users for maintaining and operating.
We selected Snomed CT, as it is a large clinical terminology system containing formal definitions for clinical concepts using hierarchical and non-hierarchical relationships.
The NCI Thesaurus is a large reference terminology and biomedical ontology developed by the NCI as part of Enterprise Vocabulary Services EVSS) http://www.cancer.gov/cancertopics/cancerlibrary/terminologyresources, and is used for data systems by the NCI and others.
Organizing the descendants of a concept under a particular semantic relationship may be rather arbitrarily carried out during the manual creation processes of large biomedical terminologies, resulting in imbalances in relationship granularity.
