and hence were not able to
test the suitability of this ontology for searching. Instead, another set of ontologies was
selected. They were supposed to cover topics of interest to test search applications (i.e.
ambiguous terms that are commonly used and hence can be a challenge for common
search engines), and the topics should be commonly known - that is rare topics should
be avoided. Furthermore, the ontologies should be of different types and ideally used in
other research projects. We chose to exclude ontologies with several thousand entities
since they were not believed to provide any significantly new insight except that of
processing time, which is not a focus of this work. Based on these criteria a set
ontologies (see Appendix I) was selected and used throughout the experiments
conducted as part of this work.