This article describes a study clarifying information systems (IS) designers’ conceptions of human users of IS by drawing on in-depth interviews with 20 designers. The designers’ lived experiences in their work build up a continuum of levels of thought from more limited conceptions to more comprehensive ones reflecting variations of the designers’ situated knowledge related to human-centred design. The resulting forms of thought indicate three different but associated levels in conceptualising users. The separatist form of thought provides designers predominantly with technical perspectives and a capability for objectifying things. The functional form of thought focuses on external task information and task productivity, nevertheless, with the help of positive emotions. The holistic form of thought provides designers with competence of human-centred information systems development (ISD). Furthermore, the author hopes that understanding the IS designers’ tendencies to conceptualise human users facilitates the mutual communication between users and designers.