Duality of task- and discourse-based interaction design for GUI generation

In general, Interaction Design is considered important for achieving usable user interfaces, but in terms of specification languages for this purpose, there is not much agreement. In contrast, for more specific Interaction Design in the context of automated (G)UI generation, Task Models are the most widely used approach. The more recent Discourse-based approach in this context is much less widely understood. It focuses on the specification of (classes of) dialogues in contrast to tasks for modeling activities that can be performed by the user or the application (system). We identified a duality of Interaction Design according to these approaches to high-level modeling for GUI generation, which we explain and elaborate in this paper. In this course, we contrast the different models, which specify largely corresponding abstractions of Interaction Design, but from different views and with a different design philosophy. As a consequence, mutual understanding of these different modeling approaches should be improved. Based on this duality, suggestions for mutual improvements can be made, so that the tool-box of interaction designers wishing to have GUIs generated automatically from their models should become more general and flexible.