{{#reviewabout:Submissions:Define Hybrid Class Resolving Disjointness due to Subsomption|}}
Overall suggestion (score): 1 - needs minor revision
This is a non-trivial decision, which is borne out by lower than expected levels of agreement between experts (see http://www.eswc2007.org/pdf/eswc07-voelker1.pdf). In description logics two classes are considered as disjoint iff their taxonomic overlap, i.e. the set of common individuals, must be empty in all possible worlds. As soon as there exists an instance in the extensions of two disjoint superclasses, the engieer is confronted with the following choices: 1. the disjointness axiom should be deleted, which will negatively affect consistency checking and the automatic evaluation of individuals in a knowledge base with regards to a given ontology (again see (http://www.eswc2007.org/pdf/eswc07-voelker1.pdf))
2. the proposed pattern should be used. This pattern allows to maintain the original disjoint superclasses while indirectly allowing an instance to be in the extension of both. This goes against the principle of disjointness, but may be convenient in the case where the ontology is imported from another URI.
The pattern defines a hybrid class as a union of the definitions of the disjoint classes. The proposers should indicate more precisely what these definitions consist of. Do they consist of all properties and restrictions? Is this equivalent to creating a class AnimalOrPlant, or AnimalAndPlant? Is there a difference between the two?
Maybe a third option to be taken into account in the discussion is the introduction of degrees of disjointness.
'Ontology Design Patterns'