Hi Poorna,
Yes, this is desirable.
Normally what you have is one model. In the real world (not necessarily for this assignment) you may have multiple views for that model. Each view would normally send events to the model via it's own controller. If the model just "returned" data to the view via the controller, then the other view(s) will be out of sync.
The solution is the observer-observable design
pattern.
The model is observable, and each view registers itself with the model as an observer. Whenever a controller sends an event to the model that modifies the current data set, the model will fire a changed event to each observer that registered with it.
There were some recent posts in this forum discussing limitations of the Observer interface & Observable class provided by Sun. They also discuss the whole MVC pattern fairly thoroughly. Try looking at
MVC topic for more information.
Regards, Andrew