In-depth Interview: Expert opinions and the research of sensitive topics
In contrast to the focus group an in-depth interview allows the concentration on a single respondent. An experienced research consultant moderates the in-depth interview in a conversational style that allows dynamic sequence of the topics mentioned in the interview guide. In-depth interviews are useful for capturing the opinions of experts or if detailed information about consumer needs and product users is required. Also, when discussing sensitive topics such as medicinal issues, or competitive intelligence in a highly contested market an in-depth interview is the better choice than a focus group.
It’s possible to do the in-depth interviews via telephone, face-to-face in the test studio or at work (or at home). Preferably, the environment that best corroborates the interview is chosen.
Interviewer and respondents have a semi-structured conversation during which the respondents functions as the expert of the topic of the discussion. This atmosphere makes it possible to address unforeseen questions, interests, and new insights. The interviewer uses interview techniques just like in the focus groups as needed.
One of these techniques is the so called Laddering (from ladder). The interviewer tries to uncover the connections between the objective benefit of a product and the consumer’s underlying attitude.
The term laddering describes the cognitive ladder. It starts with the product features that are related most closely. With each step of the ladder the respondent moves further away from the original product benefit; the interviewer leads the respondent closer to the underlying emotional benefit structure. In order to uncover the underlying emotional benefits the interviewer confronts every mentioned item with the question, “Why is that important to you?” In this way hidden motives and attitudes are revealed.
With the help of an algorithm the answers can be summarized in a Hierarchical Value Map that shows the relation between product or services features and respondent’s expectations and ideals. The results help to develop ad concepts optimally targeted at the respective consumers.
Another qualitative method is the Triads Comparison, which is used to determine product features. During this approach the respondent is shown three products or service offers. He or she is then asked to describe all those features/ characteristics in which two of the products are similar but differ from the third. This exercise is repeated with further product/ service offer triplets until the respondent no longer perceives any differences. The Triads Test can also be used as an introductory step to laddering.
LENGTH OF INTERVIEW AND SAMPLE SIZE
The length of in-depth interviews varies between 30 and 120 minutes, depending on the complexity of the topic. Typically, between 10 and 20 persons are interviewed.