How Long Should an In Depth Interview Last​

An in-depth interview should typically last 45 to 90 minutes, long enough to explore complex topics thoroughly without overwhelming the participant. This time frame allows interviewers to build rapport, ask thoughtful follow-up questions, and capture detailed insights while keeping the conversation focused and productive. The ideal length ultimately depends on the interview’s purpose, the subject matter, and the interviewee’s availability, but staying within this range balances depth with engagement.

Why Interview Length Matters

The length of an in-depth interview has a direct impact on the depth, accuracy, and reliability of the insights collected. An in-depth interview that is too short will diminish the amount of information collected regarding the feelings and actions of an interviewee due to it feeling rushed. Likewise, an in-depth interview lasting too long can cause interviewees to tire out and affect their ability to give honest and clearly laid out answers regarding their thoughts, feelings, actions, etc. It is very important to find the appropriate time duration when conducting qualitative research in order to achieve the highest quality results.

The Ideal Duration for an In-Depth Interview

Many professional researchers suggest that a qualitative one-on-one interview is best conducted within a time frame of between 45 minutes and 90 minutes, as this gives participants adequate time to respond to questions regarding various options and motivations while not making them feel burdened.

Factors That Influence Interview Duration

While the typical range is reliable, several elements can affect the interview duration in real projects. When working on projects in the real world, there can be a range of variables affecting how long you’ll be interviewing. If you’re interviewing about a product that has many aspects or is very sensitive to people, then you may need to dig deeper into those topics. Also, B2B interviews, especially with senior-level professionals, usually require longer sessions because of the technical details and the strategic aspect of the interview.

The respondent’s experience is also an important consideration. If a participant has no experience or understanding of the subject matter, it may take them longer to explain what they think; however, if they are knowledgeable and experienced with the topic, they will likely be able to provide a wealth of information quickly.
In order to conduct interviews that maximise productivity, it’s important that the interviews are designed with the differences in mind.

Structuring Time in an In-Depth Interview

A well-organized structure helps keep the conversation natural while ensuring all research objectives are covered. A typical effective interview structure might include:

• 5 minutes for introductions and rapport-building
• 10–15 minutes for background questions
• 25–40 minutes for core discussion topics and deep probes
• 5–10 minutes for closing questions and participant reflections

This flow maximizes productivity while keeping the qualitative interview timing within a comfortable range for respondents.

Signs an Interview Is Going Too Long

Gaining insight is the main focus of this research interview and we want to ensure we do not tire our participants out. If the participant starts providing short answers, showing a lack of interest, or indicating fatigue this may indicate the research interview has been going on long enough and it has gone beyond the optimal length. Thus, we need to be respectful of the participant’s energy so we can maintain the quality and integrity of the data we obtain.

How Nexus Expert Research Ensures Optimal Timing

At Nexus Expert Research, we design interview guides that balance depth with clarity. Creating effective interview guides that strike a balance between thoroughness and conciseness, seeking to maximize the utility of each moment during the interview session. In addition, we consider how to maintain motivation and momentum throughout the entire interview process, as well as designing questions that are relevant to the topic and feel conversational, thereby achieving reliable research results. 

Through our focus on specific objectives, organization of topics in a logical order, and strategic question construction, we help our clients obtain useful information from respondents in a manner that is respectful of the respondents’ time and energy and is designed to facilitate the respondent’s ability to provide feedback on the research.

Conclusion

So, how much time is an in-depth interview supposed to last? Generally, an in-depth qualitative interview should take place between 45 and 90 minutes, as this range allows for the best possible results based on the complexity of the subject matter being discussed and who is conducting it. This duration allows for a higher quality of insight, a more seamless conversation between an interviewer and respondent(s), and ultimately, improved data quality, all of which are critical components of any successful qualitative research initiative. 

Businesses that engage Nexus Expert Research to conduct a series of well-organized interviews obtain detailed insight into their operation, while also increasing their confidence when making informed business decisions.