In-depth interviews are an excellent source of primary data for researchers looking to answer more complex or open-ended questions, but only if best practices are followed. If you are looking for ways to improve the quality, accuracy or relevance to your in-depth interview responses, read on to learn four of the most important guidelines you should follow.
Focus on Questions That Bring Out the Core Strengths of In-Depth Interviews
Researchers should consciously take advantage of the strengths of in-depth interviews while steering away from inquiries that could be better answered in other primary research formats. Your questions should therefore not have quick “yes or no” quantitative answers, but rather plunge deeper to discover responses that cannot be gleaned through observation, like:
- Inner thoughts
- Contextual opinions
- Causal explanations
- Unobservable or difficult-to-observe behaviors
- Historical behaviors and other past information
Most of all, let your subjects talk. Instruct the interviewer to maintain silence once the prompt has been read, to wait five or more seconds during periods of silence before speaking and to encourage the interviewee to “go on” when responses fall short of expected length. Request that subjects “think through” their answer aloud and explain their thoughts from start to finish.
Use a Semi-Standard Structure to Create Comparable Responses
Completely unstructured interviews are great for single or limited subjects who have time for follow ups. For larger interview pools with general public participants, you will want more structure. This structure increases the chance of reaching study goals while creating more standardization among response types so that they can be directly compared.
Start with written out main questions that are asked in the exact same order. Give the interviewer freedom to ask follow-up questions based on a few prompt ideas so that subjects can expound as they see fit given the “tempo” of the interview. Encourage open-ended questions and responses, especially for follow-up prompts, but try to ask the same set of general questions every time.
Bias among interviewers and respondents is a major potential weakness of interview research, especially in-depth interviews. You can eliminate many sources of bias by focusing on the questions. “Good” interview questions:
- Ensure all questions are readily understood in the same way by a wide range of demographics
- Do not make include presuppositions or assume that all subjects will have the same context
- Ask only one question at a time
- Avoid “loaded” statements that imply positive or negative qualities to certain contexts
- Have reworded questions available for subjects who are confused, so that all rephrasings are standardized
Further bias can be mitigated by establishing a certain interview environment. Make respondents comfortable, both physically and emotionally. The researchers should appear professional so that interviewees are confident that honest responses are all that is expected. Emphasize that honesty is valued to further encourage accurate responses.
Also, inform them of the efforts you take to maintain privacy, such as eliminating identifiers or including privacy provisions in consent forms. Finally, discourage “pleasing” behavior by participants or “seeking” behavior from researchers by having interviewers who have no vested interest in the study outcomes.
Ensure Quality Data by Avoiding Common Mistakes
You can learn more about conducting high-quality interviews or high-quality studies in general by watching our video about The Five Most Common Market Research Mistakes to Avoid.