A Proposed Structure for Learning Objects Using Ontology for Effective Content Discovery

One of the major challenges in e-learning development is search and discovery of an appropriate learning object among the distributed content repositories. Although SCORM presents some approaches for content reusability, but efficient searching process is a significant problem yet. We need an effective searching mechanism for discovery and access to the required learning resources, to utilize them in our courses. But resource discovery within a heterogeneous collection of resources is a challenging problem. Semantic web has been proposed for resolving problems. Some approaches like ontology were proposed to overcome heterogeneity. Ontology represents a set of concepts within a domain, and also the relationships between those concepts. Therefore, by using ontology for metadata of learning objects, we can enrich the information content of the learning objects, and develop a better search methodology. In this work, according to our proposed ontology, we consider the structure of the learning materials in three levels: Learning Object, Content Object, and Content Fragment. Content Fragment is a content unit in a most basic form. Navigational elements enable the sequencing of content fragments in a content object. Therefore, the Learning Objects aggregate Content Objects to cover a learning objective. By focus on the structure of the learning materials, different kinds of learning materials were created. By using ontology, for these learning materials a rich metadata were shaped. By means of this kind of learning materials our ontology could be evaluated for effective searching.