Types of Interviews

In-depth interviews are used a lot during research and evaluations. They can be structured, semi-structured or unstructured.

Depending on your goals, you can elect for any of these types of interviews. Each has its pros and cons.

If you have multiple interviewers and you wish for more standardisation in the data collection, then I recommend you go for the structured interview. This way everyone is literally reading from the same script and you can collect from larger numbers of people. Comparison and analysis of the results of interviews may also be easier due to the standardisation of the questions. The big drawback though is the lack of flexibility.

Structured interviews with the set questions can resemble a questionnaire that is used in a survey. There is little to no room for probing or asking follow up questions. As such, unexpected issues or findings may not emerge. You literally get what you ask for.

So if you are going for more depth and greater understanding of a subject matter, the semi-structured and unstructured interview styles may be better options. However, keep in mind that data analysis and interpretation may become more time consuming due to the lack of standardisation. However, there are several qualitative analysis software on the market now to assist with this.

From my experience, semi-structured and unstructured interviews require more skill on the part of the interviewer and are less suited if you have multiple interviewers questioning large numbers of persons. The safest bet in my eyes is the semi-structured interview. There is some standardisation of the questions, but there is also flexibility to add questions as the conversation organically unfolds.