InterViews (An Introduction to Qualitative Research Interviewing) by Steinar Kvale (1996).

Page 145, Box 8.1
Quality Criteria for an Interview
- The extent of spontaneous, rich, specific, and relevant answers from the interviewee.
- The shorter the interviewer's questions and the longer the subjects' answers, the better.
- The degree to which the interviewer follows up and clarifies the meanings of the relevant aspects of the answers.
- The ideal interview is to a large extent interpreted throughout the interview.
- The interviewer attempts to verify his or her interpretations of the subject's answers in the course of the interview.
- The interview is "self-communicating" - it is a story contained in itself that hardly requires much extra descriptions and explanations.