Isabel Cristina Siqueira da Silva, Carla Maria Dal Sasso Freitas(2011). Using Visualization for Exploring Relationships between Concepts in Ontologies. IV ’11 Proceedings of the 2011 15th International Conference on Information Visualisation,317-322.
The most important achievement of this paper is 2.5D scheme applied to an ontology hierarchy/graph.
This paper focuses on visualizing the hierarchy of the ontology and the relationships between concepts employing multiple views. For the hierarchy, it employ the 2D hyperbolic tree which reduces the cognitive overload and the user disorientation that might happen during the interaction with the nodes, expanding and contracting it, especially in ontologies with many concepts(Figure 1a).
It use a third dimension to display one or more relationships (object properties) selected by the user in a second view. To view them, it take the plane where the tree is displayed and perform a 90° rotation around the X-axis (Figure 1b). The rotated plane, positioned in 3D as an XZ-plane, displays the hyperbolic tree, and selected relationships are represented as curved lines in space, connecting the related concepts, without interfering with the display of the hierarchical relationship.
Figure 1c shows the proposed 2.5D scheme applied to an ontology hierarchy/graph.
(I can’t upload the image, so you have to read it from the full text.)
The use of 2.5D visualization might be a solution to common problems presented by 2D and 3D ontology visualization tools, mainly cognitive overload and user disorientation.