Design research is not simply concerned with speculations regarding the relationship of theory and practice. Design research also brings out significant questions regarding the nature of research and the position of the doctorate in university education. This paper presents analyses of examples of objectivist, constructionist, and subjectivist theories of design research. The assumptions that underpin their perspectives are outlined, their powers of generalisation considered. The implications for the position of the design discipline in relation to the greater academic community, and the characterisations of design practice that they contain, are drawn out. The paper concludes by considering the pedagogical implications of the role of disciplines in the knowledge building cycle between research and professional practice.