The depth-interview, as a qualitative marketing research method, is perfect for exploring detailed information about a specific studied public, about consumer thoughts and behaviors. Even if it is not one of the cheapest marketing qualitative research methods, depth interviews collect complete information about particular goals. Prior to applying this method, we have the following priorities: we need to identify the subjects to be interviewed, as well as the necessary information to be obtained, which will turn into market research objectives and later in questions and tasks.
The depth interview guide has to be divided into moments and time intervals, and questions and tasks should be grouped by goals, for further analysis. The recommended sample of this qualitative research method is between 15 to 60 interviews. The key to the depth-interview is that the interviewer listens actively, but without interrupting. The psychologist has to reassure the participant that his experiences, whatever they are, are exactly what he is interested in. It is better to say, “Tell me about this …” than “What do you know about this …?” . The discussion must encourage the respondent to confess and talk freely, not to feel like interrogation. The subject must also be reassured during the conversation that the interviewer pays attention and listens actively.
Among the benefits of the depth-interview we mention: collecting more detailed and higher quality information than other research methods, discovering subjective experiences that can develop very quickly into valuable marketing insights, applying additional questions or follow-up questions where the interviewers feels like they need to explore more, the respondents can talk freely and the relaxed atmosphere of the discussion helps reaching the target, the topics can be sometimes sensitive, interviewers can also monitor changes to tone and word choice, or focus on body language to get a deeper understanding, there can be avoided the potential distractions that sometimes emerge in a focus group.
Brand Behavior specialists recommend that the qualitative research depth-interview should be as dynamic as possible, involve the respondent actively, and besides the discussion, there must be various projective psychology tasks or scenario-based tasks concerning the brand or product.