I need to design my case experiments to address both a simple ontology and a complex ontology. How can I quantify ontologies in terms of the number of classes, entities, etc?
I confirm the answer provided by Jasmin Cosic and I join his idea. But I add that if you want to assess the complexity of one ontology or more, it will be appropriate also to take into account what is called the granularity degree of an ontology. This degree varies from one ontology to another according to fineness of description and/or modeling adopted by the ontology developer. Hence, the notion of ontology complexity is relative. For example, you can have two ontologies that describe the same theme and the same context but with two different granularity degrees. This also leads to define the structuring level of ontologies.