Using Visualization for Exploring Relationships between Concepts in Ontologies

Usually, ontologies are represented as static 2D graphs, being the relationships exhibited as overlapping edges, which may cause a cognitive overload. On the other hand, 3D representations can also lead to confusion in terms of navigation due to occlusion. Moreover, as the ontologies grow, incorporating new concepts (and their relationships), the visualization complexity increases either in 2D or in 3D. In this paper, we discuss a visualization tool for exploring relationships between ontology concepts. We employ linked tree structures that capture the hierarchical feature of parts of the ontology while preserving the different categories of relationships between concepts. Ontologies are displayed as trees on a plane, representing only the hierarchical relationships between concepts, allowing the user to explore other connections by creating projections of nodes (concepts) in another plane and linking them according to the relationships to be analyzed.