Mapping local ontologies: Authentic semantics for learning object evaluation

Currently, there are no feasible subject taxonomies for learning objects. Large and standardized library classification systems do not present subject descriptors matching varying local practices. When searching for learning objects, teachers, instructional designers and students prefer to use subject terms with which they are already familiar. This research describes the form and function of a mapping ontology created to translate between a central subject ontology and a local subject ontology. An implemented case shows how the mapping ontology can allow teachers working with the British Columbia Ministry of Education science curriculum to search and evaluate learning objects catalogued in a repository (eLera) according to a modified form of Dewey Decimal Classification. An information retrieval evaluation showed that subject search with ontology mapping has greater retrieval precision level than simple keyword search. A usability survey showed a strong user preference for subject search with ontology mapping over keyword search.