Structured interviews are a means of collecting data for a statistical survey. In this case, the data is collected by an interviewer rather than through a self-administered questionnaire. Interviewers read the questions exactly as they appear on the survey questionnaire. The choice of answers to the questions is often fixed (close-ended) in advance, though open-ended questions can also be included within a structured interview.
A structured interview also standardises the order in which questions are asked of survey respondents, so the questions are always answered within the same context. This is important for minimising the impact of context effects, where the answers given to a survey question can depend on the nature of preceding questions. Though context effects can never be avoided, it is often desirable to hold them constant across all respondents.