There are two general models describing the behavior in this situation.
-
Replacement - the ``American'' school of OOP - the child class
replaces the method in the parent class.
-
Refinement - the ``Scandinavian'' school of OOP - behavior of the
parent class and the child classes are merged to form new behavior
Generally, if replacement is used there is some mechanism used to provide
refinement, whereas if refinement is default then replacement is not
possible.