Software Concepts

A sum up of software concepts might be interesting for trying to transfer them to other areas of knowledge.

Level	Type	Comparision & analogy	independent ?	connected ?	action	permanent ?	owner ?	UML	my simple graph
concept or instance	Dependency	Temporary utility interaction	yes	no	uses-a	no	no
instance	Association	Dependency that keeps track of the object; A worker may change company	yes	yes	knows-a uses and keeps a pointer	yes	no
instance	Aggregation	Association with ownership of the object; Suns can't have several parents but live independent life	yes	yes	has-a uses and vinculates with pointer	yes	yes, but can share
instance	Composition	Aggregation that selfcontains the object; If father dies, children also die	no	yes	owns-a uses and embeddes in memory	yes	yes
concept	Inheritance	I inherite many traits from my father but have extra of my own	- (no @ conceptual level; yes @ instance level)	- (yes @ conceptual level; no @ instance level)	(transitive generalization) is-a	yes	no
concept	Instantiation	I want a Border Collie named Bobi; I classify Border Collie as a dog bread (I want a bread named BC)	-	-	(non-transitive classification) is-a	yes	no
concept	Instantiation - class	Class factory	-	-	creates-a	yes	no
concept	Realization	Interface Implementation	-	-	(transitive generalization?) is-a	yes	no

Is-a can mean 2 logically different things:

[C] - Classification

[G] - Generalization

Right:

If: Bobi is a Border Collie (BC) [C]

And: Every BC is a dog [G]

Then: Bobi is a dog [C]

Wrong:

If: Bobi is a Border Collie (BC) [C]

And: BC is a Bread [C]

Then: Bobi is a Bread [C]