design research into three main categories, based on people, process and products: - design epistemology – study of designerly ways of knowing - design praxiology – study of the practices and processes of design - design phenomenology – study of the form and configuration of artifacts." And he emphasizes (1999: 7): "... that we do not have to turn design into an imitation of science, nor do we have to treat design as a mysterious, ineffable art. ... ... we must avoid totally swamping our research with different cultures imported either from science or art.