Ontology Mappings to Enhance Interoperability of Knowledge Domain Taxonomies Jerry Z. Li 1 , Dragan Gašević 1 , John C. Nesbit 1 , and Griff Richards 1,2 1 Simon Fraser University, Canada 2 British Columbia Institute of Technology, Canada {jerryli, dgasevic, nesbit, griff}@sfu.ca Abstract: When searching for learning objects, teachers, instructional designers and students prefer to use familiar subject terms rather than learning a new schema. This paper describes the form and function of a mapping ontology that was created to translate between a central subject ontology and a local subject ontology. An implemented case demonstrates how the mapping ontology can allow teachers using local terms from the British Columbia Ministry of Education science curriculum to search, evaluate, and register learning objects catalogued in a repository (eLera) by a modified the generic Dewey Decimal Classification. The enhanced interoperability lowers the threshold for teachers to search learning object repositories and has potential as a technique for linking less formal “folksonomy” indices. Introduction Humans have a long history of using classification systems. Early classification systems can be seen in the systematic categorization of organisms by botanists and philosophers, such as Carolus Linnaeus [1], Charles Darwin [2] and Aristotle [3]. The original purpose of biological classification was to organize the huge number of known plants and animals into categories that could be named, remembered and discussed easily, and to suggest relationships that could be identified among organisms. Classification methods evolve with advances in knowledge. Where once the classification of organisms was as simple as dividing animals into walkers, flyers, or swimmers, potentially they can now be classified by macromolecular data such as protein variation or nucleic acid sequences. Whether the classification system reflects intrinsic relationships among organisms or an arbitrary system of user preference, classification remains a conceptual tool for the reduction of complexity. The classification of the natural world has laid the foundation for modern science. The modern library system stores and retrieves material using subject matter classification systems so that books can be found quickly and easily. A library’s classification system "divides all knowledge into precise categories and subcategories. Each category is called a 'class' and each subcategory is called a 'division' or 'subdivision.'" [4]. In 1872, Melvil Dewey drafted the Dewey Decimal System [5]. It divides all knowledge into ten main classes numbered from 000 to 900; these ten primary classes are then split into divisions, which can be subdivided even further through the use of decimal numbers. It has been used in many public libraries. Most university libraries use the Library of Congress Classification System (LoC) [6]. Devised in 1897, it uses combinations of letters and numbers to represent subject areas. It divides all knowledge into 21 main classes indicated by a single letter of the alphabet; these main classes are broken into principal subdivisions by a second letter. While the LoC provides for more subclasses and hence more precision