Define User Roles II
We suppose that the content handled by the viewer object were produced by scientists from Syracuse therefore the role of the creator is assigned to them. The two other groups have the observer roles.
The shared object `viewer' behaves in different way depending on the role of the user. The user that has the role of the creator (must belong to `syracuse' group) obtains access to the viewer interface with more functionality. This extended functionality enables presenting the gathered material to the observers.
On the other hand, observers obtain access to the simpler interface suitable only for viewing the content presented by the creators.
The shared object `chat' does not have this distinction. All users (that belong to the previously declared groups) can access it in the same way without any limitations.