Interaction design is a complex and challenging process. It encompasses skills and knowledge from design in general as well as from HCI and software design in particular. In order to find better ways to support interaction design and propose methods and tools to further the research in this area we must first better understand the nature of interaction design in practice. In this paper we present two small case studies which attempt to analyse design and decision-making through the lens of one particular theoretical framework. The framework seeks to focus design activities via its artifacts and the design spaces that exist in order to support reasoning about the process and the evolution of the artifacts. Our case studies show that we can use such a framework to consider real-world design projects, and also that there are further considerations that might usefully be included in such a framework.