Abstract The capabilities of multimodal applications running on the web are well delineated since they are mainly constrained by what their underlying standard mark up language offers, as opposed to hand-made multimodal applications. As the experience in developing such multimodal web applications is growing, the need arises to identify and define major design options of such application to pave the way to a structured development life cycle. This paper provides a design space of independent design options for multimodal web applications based on three types of modalities: graphical, vocal, tactile, and combined. On the one hand, these design options may provide designers with some explicit guidance on what to decide or not for their future user interface, while exploring various design alternatives. On the other hand, these design options have been implemented as graph transformations per-formed on a user interface model represented as a graph. Thanks to a transformation engine, it allows designers to play with the different values of each design option, to preview the results of the transformation, and to obtain the corresponding code on-demand.

Modeling engineering systems requires creativity and ingenuity, and therefore involves steps that are hardly suitable for automation. However, these steps are complemented by a multitude of routine tasks. Automation of these routine tasks, if tailored to complement non-automated tasks, allows the modeler to focus on the creative and innovative aspects of modeling and design. To this end, three important principles for automated modeling have been formulated and incorporated in the MAX (Modeling and Analysis eXpert) system: – The polymorphic modeling concept provides hierarchical models, in which each subsystem consists of a type, defining essential properties, and a specification, defining incidental properties. Subsystem types can be organized hierarchically in a library, and each type can have multiple specifications. – Information about a model is processed using multiple formulations. Different formulations of one model can be used simultaneously. The task at hand determines which formulation is appropriate for inspection and manipulation. – By embedding equations in networks in an intuitively appealing way, MAX provides the same kind of support for network models and equation models. The utility of these concepts is demonstrated in a case study involving a fourth order servo system.

During the process of developing new solutions, the designer creates different representations of the design object, which have a high variation in their level of abstraction. These representations have great impact on reaching the project targets. Therefore, it is important to understand how the designers create these representations for the problem solving, in order to derive general ways of proceeding. This paper describes the assessment, classification and analysis of designer’s proceedings during the process of problem-solving, based on two examples from the industry. The evaluation contains the created representations, as well as the proceedings for the problem solving. The results show, what level of detail and what scope is to be preferred by the designer, for representing the design object during the different stages of the problem solving. Furthermore, it is shown, in what order problems are solved during the design process.