How to conduct an in-depth interview

An in-depth interview is primarily used for a more detailed examination of a research problem through a researcher's interview with one respondent. Thanks to this method, we understand how our respondents think about their concerns and needs, and based on that, we can set hypotheses that will help us develop our product or service.

Lucia Marcinková

UX Researcher

What is this method for?

We classify in-depth interviews as a qualitative method. We usually work with 5 to 8 respondents from one target group. However, the total number of respondents may vary based on the repetition of the respondents' answers. 

The interview can take various forms. We most often distinguish these three types:

  • Semi-structured  – we have prepared questions and topics we want to discuss with the respondents in advance. We can freely skip some questions according to our needs and the respondents' answers
  • Structured – we prepare the questions and their order relatively accurately
  • Unstructured – we do not know in advance what topics we will touch on. For example, our topic is eating, but we do not know whether we will talk with the respondents about restaurants, healthy eating, fast food, diet planning, or their favorite food. The aim is to find out how far the problem goes and what it entails. 
    The in-depth interview is not used to determine how widespread the problem is or how many respondents have encountered this. In this situation, it is appropriate to use quantitative research methods.

In-person and online

Also, the interview form may differ depending on whether you meet with the respondents in person or online. At DesignDev, we have experience with both in-person and online in-depth interviews. The undeniable advantage of online surveys is that you can reach a broader range of respondents due to distance and time constraints. On the contrary, while conducting in-person research, the advantage is that you do not have to worry about the speed of the internet or the failure of technology.


What does the whole in-depth interview process look like? The first phase of any research is its preparation. It is important to determine what we want to achieve through in-depth interviews and what information we want to find out. We should make goals accessible to all stakeholders and visible throughout the whole process, for example, placement on an office wall. Once the goal is clear we can take the necessary steps to achieve it. In addition, to important topics I recommend including specific questions, which can help you dig deeper into a problem that might arise. Respondents will become more invested in a process and want to share. Part of the preparation of any research is the recruitment of respondents. Here we define a target group, where and how we address them, specify a reward they receive, and where the research will take place – whether online or in-person. In the case of in-person research, it is necessary to think about having a quieter environment and offering snacks. The last step of the preparation is to negotiate a specific date and time with the respondents and prepare possible confidentiality agreements, which respondents should sign before any interview.

The research process 

Then the research process begins. I recommend checking the functionality of the interview recording technique once again.

  • At the beginning of a meeting, it is important to briefly explain to the respondents what the interview will look like, what topics we will touch on (specifically if we ask them sensitive or personal questions), and tell them about the recording.
  • After this introduction, we ask general questions that are designed to put them in a narrative mood and relieve any nervousness.
  • The introductory questions are followed by the specific questions that form the core of our research problem. These questions are the largest part of our conversation. We must reserve sufficient time and try to discuss them in as much detail as possible. It is important to ask the respondents open questions. For example, start a sentence with the word "how" (for example, "How did you choose your mobile phone? How did you work with this application"? And so on). Another type of successful research is to harness the power of silence. If you, as a researcher, remain silent, you give the respondents enough space to complete their answers. It is also important to tune into the respondents' emotions and current mood (for example, not to be too energetic if you see that a respondent is reserved – in this situation it is advisable to use a soft tone and leave room for them to talk).
  • In conclusion, it is appropriate to thank respondents, tell them how they can find out about the results of the research, and reward them.

There are a few key things to think about in an in-depth interview. It is important that the conversation takes place naturally and questions follow each other. It is perfectly fine not to use the questions in the exact order they are given. Instead, we need to record which points we have already discussed and which we still need to focus on. I also recommend not underestimating the preparation phase – from setting a goal to recruiting respondents to write a script. As researchers, we must also keep in mind that our goal is to solicit quality data and not superficial answers. 


The last phase is the evaluation of the interviews. Personally, I work with the Miro tool, where I put each statement verbatim (literal statement of the respondents) on a sticker. I then combine them into thematic areas and attribute opportunities to them. Opportunities then serve as a basis for further development of the product or service.

An in-depth interview is just one of the methods we can use as researchers. However, there are many other quantitative and qualitative methods, and it is up to us to choose which is the most suitable for our situation. An example is the focus group method, in which a few respondents are in a group with a researcher – usually a group of 6–8 people. We also try to go in-depth and give the respondents space to express their attitudes, needs, and opinions when using this method. The respondents were chosen because their opinions usually defer from each other, this will help us to get a variety of views on the same problem. We gradually obtain similar information from the respondents during the in-depth interview.


  • David Travis & Philip Hodgson – Think like a UX researcher
  • Jan Hendl – Kvalitativní výzkum: základní metody a aplikace

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About the author

Lucia Marcinková

UX Researcher

Lucia conducts user research for better understanding of users' needs and pains.

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