Expert interviews are a good example of the way in which the everyday practice of social research and theoretical consideration of this practice do not always run parallel to one another. The use of particular methods sometimes precedes their general theoretical reflection. For many years, the widely held view was that expert interviews were conducted frequently but only rarely thought through (Meuser and Nagel, 1991). Only in recent years has the debate about expert interviews gradually become more concrete (see Bogner and Menz, 2008). However, this has certainly not led to a situation in which the different definitions and methodological conceptions of expert interviews have moved closer together. Even today there are disputes not only about how expert interviews can be placed on a secure methodological footing, but also about whether this is even possible in principle.