isA relationship: how can we model it in protege? What is its difference with Instance?

Question

For modelling an isA relationship, (1) is it enough to just make sub-properties or sub-classes? If not, what is the correct way?

(2) What is the difference of isA and Instance? From what I understood, isA is a predicate for objects whereas Instance is for demonstrating individuals. But I am not sure.

Thanks.

Can you include an example what you mean with "to just make sub-properties or sub-classes"? And what does "demonstrating individuals" mean? — Stefan - brox IT-Solutions, Aug 18 '22 at 22:44
For example, is "isA" relationship same as `rdfs:subClassOf` or `rdfs:subPropertyOf`? — Arbo94, Aug 18 '22 at 22:57

score 1 · Accepted Answer · answered Aug 19 '22 at 08:51

Yes, to make a sub-class, it’s enough to use the rdfs:subClassOf property.

# "Y is-a X"
:Y rdfs:subClassOf :X .

In Protégé, this happens automatically if you use the "Add subclass" button.

(The same goes for rdfs:subPropertyOf and the "Add sub property" button.)

The term instance refers to a member of a class.

If you say

ex:Arbo94 rdf:type :Y .

then ex:Arbo94 is an instance of the class :Y, and given the rdfs:subClassOf statement from above, also an instance of the class :X.

It’s also an instance of rdfs:Resource ("the class of everything"), as everything in RDF is a member of this class.

isA relationship: how can we model it in protege? What is its difference with Instance?

1 Answers1