4. The system set forth in claim 1 wherein: the model further includes representations of further information; and the interface permits the collaborator to view how the further information is related to the model entity and to view the further information.
4. The system set forth in claim 1 wherein: the model further includes representations of further information; and the interface permits the collaborator to view how the further information is related to the model entity and to view the further information. 13. The system set forth in claim 4 wherein: there is a plurality of types of model entities; a representation of a model entity specifies the represented model entity's type; the interface permits the collaborator to view the type of a model entity; and a related representation of further information may be related to a representation of a model entity of any type.