Design courses in engineering education provide the space in the curriculum to synthesizetheoretical and technical knowledge gained from coursework. As students gain new knowledge and acquire skillsets, there is a need to demonstrate how the learning connects to their professional actions. With practice and rehearsals, students realize the values and dispositionsthey need to possess to be deemed a disciplinary member. In this paper, through semi-structured interviews of six design instructors, we report what instructors think is the epistemic role of design courses in instilling disciplinary values in an Engineering Science program.