Abstract. In this paper, we describe an approach for ontology comprehension support called model exploration in which models for ontologies are generated and presented interactively. We also discuss the issues involved in using tableau reasoners for the generation of models for model exploration and report on a user study we conducted on our prototype implementation, SuperModel, to evaluate its effectiveness in supporting users in understanding an ontology. 1 Motivation At different stages of an ontology's life-cycle, the people working with it require some sort of understanding of it; e.g. which parts of it encode what piece of knowledge explicitly or implicitly, how it is meant to be used on its own or in conjunction with other ontologies, and if and where it is broken and how it may be fixed. Tool support is necessary to achieve these kinds of understanding, as ontologies can be as broad and complicated as the fields of knowledge they model, and as it is easy to get lost in the...