In real estate the maxim for picking a piece of property is “location, location, location.” In elite interviewing, as in social science generally, the maxim for the best way to design and conduct a study is “purpose, purpose, purpose.” It's elementary that the primary question one must ask before designing a study is, “What do I want to learn?” Appropriate methods flow from the answer. Interviewing is often important if one needs to know what a set of people think, or how they interpret an event or series of events, or what they have done or are planning to do. (Interviews are not always necessary. Written records, for example, may be more than adequate.) In a case study, respondents are selected on the basis of what they might know to help the investigator fill in pieces of a puzzle or confirm the proper alignment of pieces already in place. If one aims to make inferences about a larger population, then one must draw a systematic sample. For some kinds of information, highly structured interviews using mainly or exclusively close-ended questions may be an excellent way to proceed. If one needs to probe for information and to give respondents maximum flexibility in structuring their responses, then open-ended questions are the way to go.