Interviews are often used instead of a survey because they allow the interviewer to increase response rate and reliability. They can be the only reasonable format in some circumstance (e.g. meeting with a CEO). Most importantly, interviews can include direct observation of certain behaviors and attitudes that can lead to completely new insights.
Interviews cannot reach the scope of surveys that draw over multiple questions over hundreds of respondents of course. But even in these cases, interviews can be necessary to complement the regular survey because some of the questions might require face-to-face interaction. For example, in biomarker studies over medical patient cohorts, some questions often require complex diagnostics that can only be carried out by an expert.
A common challenge with interviews is the interviewer effect. In a face-to-face survey, participants may attempt to project a positive self-image in an effort to conform to the norms they attribute to the interviewer asking questions.
Another common challenge with interviews is the mode effect. Whether the meeting takes place under formal hierarchical corporate structure, in-person at home, by street intercept, by telephone, or even by text online, it can change how the respondents answer.
As for surveys, the questions should be simple and direct, and contain both open-ended questions which allow responders greater flexibility but are difficult to record and score, and closed-ended questions which are easier to record and score but diminishes expressivity and spontaneity.
- Articulate the overall goal of the interview and what kind of information should be collected
- Prepare a discussion canvas to structure the meeting. The opening could include the objective of the meeting, the body could be categorized by theme, each of which would direct to a specific set of questions, and the closing could solicit documents/contact information and indicate next steps, i.e. when the interviewee will hear back from the interviewer. In contrast to surveys, starting with simple demographics questions is useful to boost the respondent confidence.
- Start carrying out the interview by breaking the ice, introducing the objectives, and proposing an agenda for the meeting. Proposing an agenda makes the consultant appear rigorous but also sensitive: the interviewee can feel more comfortable when a clear beginning, objectives and milestones, have all been prepared in advance.
- During the interview, focus efforts on active listening and direct observations of behaviors, attitudes, purchase journey, etc. Take note of key ideas and if possible quote verbatim.
- Write a detailed report of the interview once the meeting has come to an end