Visualisation design as language transformations – from conceptual models to graphics grammars

In this article, we frame the process of visualisation design as a systematic transformation between two distinct domain-specific languages. As a result, we obtain a general framework, which may inform the process of visualisation design, as well as enable the creation of flexible general-purpose systems for interactive visual analytics. Our efforts aim towards raising the level of abstraction, by allowing users to express queries through a vocabulary that is specific to their problem domain. This domain-specific language is based on the conceptual model of the input data. Subsequently, a visualisation specification prescribes a language transformation, which maps from the user-defined conceptual model to the application-defined graphics grammar. The key to this approach is a formal interpretation of the conceptual data model, using rich type information in order to capture the data semantics and structure. The theoretical foundations for this approach are introduced, building on existing theories from database, type system, and visualisation literature. Subsequently, we discuss the key concepts of the proposed framework. Finally, the applications of the framework are illustrated by three use cases, which successfully applied these concepts in real-world visual analytics scenarios.