What is the difference between Structured Interview and Unstructured Interview?

An unstructured interview or non-directive interview is an interview in which questions are not prearranged.

Structured Interview is one in which a particular set of predetermined questions are prepared by the interviewer in advance.

These are my personal opinions with regard to techniques but explaining the difference in academic interest. Both the techniques are good for interview purpose.

Structured Interview

Unstructured Interview

Interviewer follows a set of predetermined questions to collect information from interviewee.

Interviewer asks questions to collect information from interviewee without following  any pattern

Interviews are having a pattern

Interviews are without any pattern.

Questions are pre-decided.

Questions are mostly  framed on the basis of the need of the hour.

Interviewer is not able to change the pattern of interview or does not change the pattern,

Interviewer is free to change the pattern of the interview.

Interview questions can be open ended or closed ended and there is room for elaboration for the interviewee.

Interview questions can be open ended or closed ended and there is no room for elaboration for the interviewee. Mostly those are the yes or No type questions.

Questions are prepared in advance.

Questions are built on the spot depending upon progress of the interview.

Interviewer may have a question bank

No Question bank

Same set of questions for all the interviwees.

There are no set Questions for this process.

There is no spontaneity in the interview process.

Questions are spontaneous and hence could be thrilling to interviewee.

Good process for Research oriented process

May Not be always suitable for Research

Comparison of responses to same questions from different interviewees is easy.

It is not easy.

This can become stereotyped for the interviewee

There are less chances of becoming sterotyped.

People find this useful in terms of reach and records of the interview.

People may not find this useful for all the interviews but this is also a good technique for certain purposes.

Little less experienced Interviewers can manage this interview.

Interviews managed by experienced interviewers will be more fruitful.

set of questions are already set for an interview are said to be structured interview and questions are not set in advance and for respondent said to be unstructured interviews.