This paper examines the fundamental nature of science, design, hence design science and design research, with a view to determining a conceptualisation of design science that is useful in the discipline of information systems (IS). After reviewing several notions of design, the paper recommends a conceptualisation that involves a broad practice-based view of design, an inclusive conceptualisation of design science, and a diverse and multi-paradigmatic approach to design research. The paper recommends that the design task in IS be conceived as one that includes rather than strips away the social and organizational context of the IT artifact, and this impacts the breadth of topics embraced by design science, and the types of methods employed to further enquiry in the field.