Can/Should I create a owl/rdfs class that would have only 1 instance

Question

I have a domain of educational institutes, where institutes would be recognized by authority. There are only 2 authorities with no specific restrictions or properties as of now. Should I create two sub-classes with only one instance each or should I create only one class with two instances?

Answer 1

The choice depends on how you foresee the ontology being used. Are there substantial differences between the authorities? Do these authorities also represent categories that might have subcategories?

At the moment you might have only one instance for each class; is this necessarily always the case, or more instances might appear in the future? The answer to these questions should drive your choice on whether the authorities should be individuals or classes.

My view, from the content of your question, is that they should be individuals.