An interactive ontology visualization approach for the domain of networked home environments

This study concentrates on the construction process of a software tool which is able to interactively visualize ontologies, particularly in the domain of networked home environments. Special attention in this study is given to the design and implementation of the interaction mechanisms between the user and the visualization. This study is carried out by using a constructive research method supported by literary review and a test case, in which the constructed approach is validated. In networked home environments domestic devices can interact seamlessly with each other and with-in home and external networks, and users can easily manage home devices, both locally and remotely. Networked home environments are described by ontologies, which are controlled vocabularies that describe objects and the relations between them in a formal way. The Web Ontology Language (OWL) semantic mark-up language was created for publishing and sharing ontologies, and it provides mechanisms for creating all the components of an ontology: concepts, instances, relations and axioms. The OWL language is complex and looking at an OWL ontology for the first time can be overwhelming. Several visualization approaches have been developed to enhance the understanding of ontologies, but these existing visualization approaches are domain independent, graph based and not suitable for visualizing ontologies that describe networked home environments. The prototype software tool constructed in this study addresses these shortcomings by visualizing ontologies in a domain-specific way. It provides extensive interaction possibilities to help users to communicate with the visualized data. This approach makes OWL ontologies more interesting and concrete, and above all easier to comprehend. The main achievement of this study is an ontology visualization tool prototype called VantagePoint. The results of the validation indicate that with VantagePoint it is possible to accurately create and visualize semantic models of real-world networked home environments. Through the extensive query construction features it is possible to access any data contained by the models. Although the validation also reveals some minor deficiencies, it must not be forgotten that VantagePoint is still in a prototype phase and further research and development work will be undertaken.