Palliative/terminal sedation has been defined as the induction, through medication, of a permanent coma in immanently dying patients suffering from refractory symptoms. Expectations are that this practice will grow considerably in the near future. To gain a deeper insight into this practice in the Netherlands and the moral dilemmas surrounding it, we sent out a questionnaire and scheduled a series of semi-structured interviews targeted at general practitioners, as well as medical and nursing staff in hospitals, nursing homes, and hospices. Employing both a quantitative and a qualitative approach is favourable in view of triangulation. But from yet another methodological viewpoint, this dual approach has appeared to be necessary, because of the following observations: - Apart from our definition of palliative/terminal sedation, many alternative definitions circulate and are used in practice, research, politics, and the media. -Because of this, there is no shared understanding of what palliative/terminal sedation is in the first place. Many respondents first start thinking about (particular aspects of) their practice when prompted by the researcher, and consequently their response may need more time to mature than the researcher has reckoned. This leaves researchers (and others) with a serious conceptual and interpretative problem, which is utterly significant in view of the moral delicacy and societal relevance of the subject. In our paper, we describe the way we have dealt with this problem, using an interactive approach, and present the results of our study. One important conclusion is that research into palliative/terminal sedation should be partly targeted at the concept and definition of palliative/terminal sedation itself. Even then, however, caution is warranted in interpreting and using research data.