The problem of collaborative knowledge management is the distributed documentation of facts according to defined schemas or ontologies. But the precise instantiation of ontologies is left to the user or the application layer. To achieve a better collaborative approach the instantiation process should be disclosed together with the ontology. The necessity of disclosure is due to the fact, that an ontology inherently implies a set of different model types. We call that fact the semantic gap in ontologies. This paper proposes a solution for a disclosure based on a generic, workflow-based description of the instantiation method: the Modelling Workflow Patterns (MWP). Based on Petri nets as information model, MWPs can be processed by generic interpreters to create valid instances of the specified model type. This paper presents an implemented architecture consuming MWPs for Topic Maps and OWL ontologies.