The design of complex interactive systems can be successfully supported by the collaboration of several teams. Each of these teams considers a specific part of the system under design specifying it continuously through a series of specification stages between the requirements and the design stages. Highly important for achieving a precise and continuous specification process between the requirements and the design stages is, however, a suitable strategy for refining abstract specifications into more concrete ones correctly and consistently. Beyond the possibility of continuous refinements the most challenging point is whether all parts of a specification treated by various respective teams are able to interact with each other in the right way thus leading to a collaborative specification process. This concerns the requirement that the interoperability of the involved parts is always given in the intended manner. In this paper human-computer interaction is modelled using the concept of information resources and is formally specified by the notation of graph grammars. In order to refine abstract graph grammar specifications of human-computer interaction wrt important requirements correctly and consistently graph rewrite rules at a meta level will be used. The formalism of graph grammars and especially the graph grammar concepts of sequential independence, parallelism, amalgamation and distribution are valuable means for showing how collaboration of teams and interoperability of the respective arising specification parts of a system can be realized. The advantage of such a continuus collaborative specification process is that local as well as global views onto the specification are possible whenever desired. In such specification processes the existence of consistency can be shown and arising inconsistencies can be managed in a suitable and flexible way at every specification stage.