This chapter introduces general principles concerning the asking of questions. It focuses on studies where the gathering of information through direct questioning, usually face to face, is the primary data gathering mode. The chapter looks at the central issue of structure face-to-face personal interviews, where the interviewee sits and talks with the interviewer, tend to be less structured situations than those where a questionnaire is formally administered. The more unstructured the approach, the more the outcomes rely on the skills of the interviewer and may be distorted through the potential effects of interviewer influence and selectivity. The relationship and interaction between interviewer and interviewee may affect the quality and amount of information obtained in an interview. Conventional research lore holds that interviewers should not engage or lead the respondent as one would in normal conversation. The semi-structured interview is the interview style of choice in much qualitative work. Interview content can be subjected to content analysis and therefore partially quantified.