In this paper we show how action research contributes to the design of health information systems by constructing knowledge addressing users' concerns in a timely manner. Our aim conducting action research is to understand the work practices of the expected users and to bring this understanding to the design, ensuring that we are enabling users rather than constraining their work. We view this process as a knowledge translation process where researchers and users exchange and create new knowledge about technology and use practices. We argue that action research can be viewed as a knowledge translation process, where researchers and users co-construct a common context for design and use of technology. By providing insights from our two years of action research focusing on the design and use of emergency department information systems within a Canadian hospital, we identify four main activities essential for creating the research context as a knowledge translation context.