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Unit 11: Domain Analysis
Notes
Notes Inheritance can be added by generalizing existing classes into a superclass or by
specialising a class into subclasses (based on taxonomic relations).
Bottom-up Generalization
It is done by generalizing common aspect of existing classes into superclasses.
Discover inheritance from bottom-up searching for classes with similar attributes,
association & operation
Define a super class to share a common feature.
Example: Remote Transaction & CashierTransaction are similar except initiation so they
can be generalized by Transaction
Top-down Specialization
It is done by refining existing classes into specialized subclasses.
Look for noun phrases composed of various adjectives on class name
Example: Fixed menu, pop-up menu, sliding menu
Multiple Inheritance
Use it to increase sharing but only if necessary because it increases both conceptual and
implementation complexity
Similar Association
When same association name appears more than once with same meaning, generalize it.
Task Compare and contrast bottom-up generalization and top-down
specialization.
Self Assessment
Fill in the blanks:
1. Names that describes individual objects are ........................
2. A class that can be derived from other class is a ........................
3. ........................ describe structural property, not an event for object.
4. If independent existence of element is important than value, it is considered as an
........................
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