It's great to see some traffic on this list. :-)

Student is a role played by a person - correct. It is never a moment-interval. A
Student might enroll for a class or have a period of registration for a degree
or a set of classes. The pink moment-interval would be the PeriodOfRegistration
or Enrollment.

The other example is interesting. To some extent you need to decide on the scope
of what you are doing. Is Address just a useful piece of data about a person?
Are you interested or not in tracking the lifecycle of the location?

For example you could describe a green thing Builing and it in turn has a
Location (green) which has a Street (green) which would have a NameAssignment
(pink) to a Name (green).

You are very unlikely to want this level of detail if you were building a system
to track eCommerce purchases. You'd only want it if you were building a GIS
system for a local government, for example.

David
http://www.agilemanagement.net/

--- In colormodeling@yahoogroups.com, "Gyula" <csomgyula@...> wrote:
>
> Hi everyone!:)
>
> Having some experience in modeling, though limited in color modeling I have a
question which seems typical for me:
>
> (At least for me) it seems that everything is changing and bound to time:
things, parties and descriptions, too. And in many cases (office-like, auditing,
etc.) systems has to preserve the older record versions and many of them needs
to store time data. How does this effect colour modeling?
>
> For instance take the Student Registration domain:
>
> From one viewpoint the Adress is a thing, from another it's a moment-interval
(for instance the street can be renamed resulting in different address versions
for the same place). How should one model this situation? What will be the
archetype of an address version?
>
> From one viewpoint the Student is a role, from another it's a moment-interval
("being a student" has a start and end date). How should one model this
situation? Should we split the student entity into a role- and a moment-interval
entity, introducing unnecessary complexity? Or should we merge them introducing
an entity having two different archetypes.
>
> Any idea? Anyone who met similar situations?
>
> Cheers,
> Gyula
>