Thank you for your answer!:)

Regarding the student question... When you refer to the term "student" do you mean the general term (the student role!) or a particular person being a student (a concrete person who is a student)?:)

Regarding versioning.. . You caught me:) My current project experience comes from the govermental area, from a large program of multiple projects. However within this context I've met the following problem domain which is not goverment-specific (at least I think it isn't) and requires versioning:

The authority we are working for does many "offline" works. Here "offline" means something that is far from the central office, and detached from the system we are building.
The general workflow is the following. The person downloads the master data from the system to his workspace, goes out, does his home work, comes back, uploads his work data into the system, which is then postprocessesed (audited, evaluated, reported, etc.).
In this context there can be a significant difference between the two dates (downloading the master data and postprocessing the work data), even a month can elapse... And here comes the trick:) The office's main activity is to check business entities represented by the master datas in the system. Thus when postprocessing someone's work results, the system must work against the master data that was valid when the work was executed. Hence the system must preserve older versions of master data.
I think this might be a general problem eg. for systems dealing with long running tasks and processes.

Opinion?:)

Cheers,
Gyula

--- In colormodeling@ yahoogroups. com, "David Anderson" <dja@...> wrote:
>
> 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 PeriodOfRegistratio n 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
> >
>