Abstraction, concretization, generalization, and specialization
are operations on concepts.
-Generalization: An existing description of a set of objects
can be further generalized by adding new objects to the set
and modifying the description to take these objects into
-Specialization: The inverse operation to generalization is
specialization. Specializing the description of a set of
objects involves the reduction of the set to a subset.
-Abstraction: An existing description of a set of objects
can be further abstracted using a new focus and filtering
away all parts of the description that are not relevant
with respect to the new focus.
-Concretization: The inverse operation to abstraction is
concretization (also called refinement). Concretization
results in the increase of detail per objects.