My main research interest lies in the building, functioning and consequences of knowledge infrastructures for the governance of health care. I have studied such infrastructures both at (inter)national (e.g. the working of science advisory bodies), sectoral (e.g. the use of performance indicators in health care), organisational (e.g. planning & control cycles in hospitals) and shopfloor levels (e.g. the implementation and use of information technologies). Currently my main interest is in organisational infrastructures for quality and safety in health care. Projects related to this agenda are studies on the regionalisation of elderly and mental healthcare and a study on task differentiation of nursing care. Also I am involved in several studies with and focused on the work of the Healthcare Inspectorate.  Methodologically, I have specialised in qualitative, mainly ethnographic research methods. I have become increasingly interested in 'interventionist' or 'action' research as well as on the study of 'complex' interventions in health care and 'mixed methods' research. I am a member of the Dutch research school of Science, Technology & Modern Culture and of the Society for the Social Study of Science. I participate in the European Health Policy Group, a group of political scientists and economists studying (comparative) health policy. I teach in several programs of the Erasmus Shool of Health Policy and Management. I also coordinate a course on Organizing for Quality in the Nfu Master program on Quality and safety in healthcare..