A semi-formal framework for describing interaction design spaces

Interactive system design is typically more successful if it is an iterative process involving collaboration between multi-disciplinary teams with different viewpoints. While some sub-teams may focus on the creative aspects of the user interface design and other sub-groups on the implementation of required functionality, all must ensure that they are working towards the same goal. They must also satisfy the requirements and needs of all stakeholders. Although many suggestions have been made as to how such design might be supported in a more formal way (such as by using a model-driven process), less focus has been given to managing the co-ordination of design sub-teams following a creative process. In this paper we propose a semi-formal framework to describe and to compare design spaces, and the external design representations within those spaces. The framework is based on ideas from interaction design and on formal refinement approaches. It suggests a distinction of design options into alternatives and variants to describe and guide processes of idea generation and convergence within, and between, different design sub-spaces and sub-groups. We provide a small example to illustrate our approach and to show how it can be implemented by using standard formal approaches alongside less formal design notations and human-computer interaction processes.