An ontology-based multi-level semantic representation model for learning objects annotation

In technology-enhanced learning, semantic annotations have been employed to attach semantic metadata to learning materials in order to significantly enhance their accessibility by human users and machines as well. In this paper, we present an ontology-based multi-level semantic representation model that aims to enrich the description of learning objects with semantics regarding their subjects, competencies and instructional roles. More specifically, the proposed model uses three ontologies: a subject domain ontology describing the domain concepts and the relations that are covered by the subject matter being taught, a competency ontology describing the competency-related characteristics of learners and learning resources, and an instructional role ontology specifying the instructional role(s) a learning object can play in an instructional setting. To demonstrate the feasibility of our model, an illustrative example is given that explains how learning object semantics can be represented with different granularities.