Classification of User Experience of a Safety Ontology

The ramifications of a safety-critical computer-based system can lead to hazards that affect both humans and the environment. To prevent or minimize the potential of these dangers from occurring, several analysis methods and techniques can be used. One analysis method is the use of ontologies. However, the usability of ontologies can hinder or prevent their use. This report investigates how the usability of ontologies can be increased to make sure that as many users as possible can use the hazard ontology, a specific ontology that focuses on safety-critical computer-based systems. This thesis covers a background study of ontologies, the hazard ontology, usability, and usability metrics in preparation for a quantitative study in the form of an experiment. The results of this experiment were then used to evaluate the usability of the hazard ontology, identify usability from a user’s perspective and how to improve it from a usability standpoint. Results of the experiments indicates that the learning curve was steep and that this could potentially be alleviated by expanding the instructions with step-by- step guides, visual examples, and feedback from ontology developers (or somebody that is experienced with the hazard ontology) during the learning period if possible. They also indicated that the user experience was improved in multiple metrics once the user had a better understanding of the concepts.