Correctness
validation and verification
Superclasses
an entity with additional meaningful subgroupings (employee)
Subclasses
a subgrouping of a superclass entity ("is a")
Disjoint
an entity must be only one of the listed subclasses
Overlapping
an entity can be a member of one or more of the listed subclasses
Specialization Process
process of defining a set of subclasses of an entity type
Top-down Conceptual Synthesis
start with superclasses and then define subclasses by successive differentiation
Bottom-up Conceptual Synthesis
start with subclasses and then define superclasses by successive generalization