Interaction design processes are characterised by multi-disciplinary teamwork and by an interplay of creative, situated and analytical thinking. Although design in the domain of human-computer interaction has been widely investigated, the focus of research has been mainly on the user’s role and several authors refer to the need for a deeper understanding of the increasingly complex interaction design processes. This paper suggests a conceptual framework for interaction design that accommodates and unifies different perspectives from general design research while considering the specificities of the domain. Within the framework, description and analysis is done through the lens of design spaces, design artefacts, and refinement relationships between design artefacts. The framework extends existing concepts of design spaces by introducing complex spaces which acknowledge that design is rarely an individual activity but is more often undertaken by teams of designers. The framework also offers a distinction between design options into alternatives and variants to better describe and guide processes of idea generation and a convergence within, and between different sub-spaces and sub-teams. Different types of refinement between design artefacts are also discussed.