Building theory in a practical science

The aim of this chapter is to consider the problem of theory building in a practical science and in information technology (IT) and information systems (IS) in particular. Theorising in IT design disciplines (practical science) is differentiated from theorising in other scientific fields in essential ways. Two modes of theorising are distinguished for design disciplines: an interior mode with the how of artefact construction studied and an exterior mode with the what of existing artefactual phenomena studied. Eight principles of theorising are advanced for theory building: 1) artefact centrality; 2) artefact purposefulness; 3) artefacts as systems; 4) design research variants; 5) differing logics; 6) types of theory; 7) mid-range theorising; and 8) interior and exterior modes for theorising. The implicit claim is that consideration of these principles will improve theorising in design disciplines-for both design researchers and researchers using more traditional methods. Some illustrative applications are provided in support of this claim.