The exploration of new types of everyday interactions enabled by the increasing integration of digital technologies with the physical world is a major research direction for interaction design research (Dourish, 2004), and a focus on materials and materiality is also of growing significance, e.g.: Internet of Things; interactive architecture; the intersection of craft and technology. Increasingly, designer-researchers from a range of material-focused creative design disciplines are starting to address these themes. Previous studies indicate that new approaches, methods and concepts are required to investigate the evolving field of physical-digital synthesis in the built environment. Addressing this, the thesis asks one central question: What resources for design research can help practitioners and researchers from multiple creative design disciplines improve the design of physical-digital artefacts located in the public realm? A detailed Scoping Study explored experimental research methods for this thesis and produced an overview of physical-digital artefacts in outdoor public space. This scoping influenced the subsequent research: an in-depth field study of the design culture and practices of fifty material-focused designer-researchers; four case studies of physical-digital artefacts in outdoor public spaces; a formative creative design workshop with fourteen participants to test the findings from the research. The chief contribution of this thesis to interaction design research is the development of two resources for design research (the Experiential Framework and the Conceptual Materials for Design Research) and the practical application of these new tools as a method for design research in a simulated ‘real-world’ creative workshop setting. Both resources are intended to co-exist and be integrated with established design research methods and emerging approaches. Hence, the outputs from this thesis are intended to support designer-researchers from a range of creative design backgrounds to conceptualise and design physical-digital artefacts for urban outdoor public spaces that provide richer interaction paradigms for future city dwellers.