Jeffrey wrote:
"UML has two composition associations. In the
aggregation, the parts exist whether the whole exists or not. A football
team still exists even after the game is over, when all the players have gone
home. In the compostion, the parts vanish. This enables constructors and
destructors in software code, for example."
If its in
the UML schema, then it must be a category mistake, to treat which the
ontology serves.
Any team is a
collection of subjects, any game is a human activity, so these different things
of different kinds hardly make a whole as a single
entity.
Any whole
incorporates the parts or elements of the same kinds and nature. There are
generally several types of wholes:
1. the wholes
made of substances or objects;
2. the wholes
composed of states (properties, qualities or
quantities);
3. the
wholes consisting of actions or processes;
4. the wholes
involving parts-relationships.
Returning to
the subject of the thread: how to model age groups. To resolve the issue, the
modeler needs to decide what is a human being:
an organic
whole of substances, or a temporal whole of states, changes, and
relationships?
Another thing, the parts are never 'vanish'. The whole
and its parts affect each other in a mutual reciprocal way. For real systems
this fundamental rule goes as the whole-part causation and the part-whole
causation mechanisms.
Azamat
Abdoullaev