Models are made cognitively acessible to humans by visual representations that allow to spatially navigate models, and affordances that enable humans to interact with models. End-user functionality provided by an information system application can be considered as on the one hand consisting of models that conceptually represent an application’s purposes, and on the other hand human-accessible interfaces to models, which enable interaction. Using an information system application in this sense means to derive information from models, store information in them, navigate to specific parts of models, invoke analysis functionality on them, etc. In other words: the tasks when operating information system applications can be understood as interactions with representations of models, this is why an approach for model representation and interaction offers the prospect of more efficient and purpose-oriented development of future information systems.
Methodologically, the definition of visual representations and options to interact with models demands for flexible means to describe the projection of models onto, e. g., spatial structures of a graphical display device. It also requires to map be able to describe the interactions that are offered by available input devices the graphical interface using semantically rich, purpose oriented terms.
The LE4MM project incorporates the development of an advanced representation and interaction interface definition approach that fulfil the above requirements. The Topology Type Definition Language (TTDL) provides language elements that allow to describe visual representations of models in terms of spatial projections and navigation steps, rather than to operate on the level of graphical primitives, which is the state-of-the-art in graphical representation definition.
The TTDL reflexively applies multi-level definition techniques to visualization descriptions. This allows for a fine-grained re-use and refinement of general visualization and interaction patterns in different conceptual domains, applicable with the same multi-level modelling constructs that are used in conceptual multi-level models and inside the same tooling environment.
The following Figure shows an example specification of the topology type of a bicycle visualization: