Content Type:

Glossary

Share Print

In-depth interviews (IDIs) Definition

A qualitative research technique in which a moderator interviews one participant. Generally lasting 30-60 minutes. Often there is a one-way mirror and observers watching the session. Also known as a one-on-one or diad.

In-depth interviews (IDIs) are one-on-one, qualitative interviews conducted to explore a participant’s attitudes, motivations, behaviors and experiences in detail. They allow researchers to dive deep into topics that require nuance and personal insight.

What are the key aspects of in-depth interviews within the marketing research industry?

• Conducted in-person, via phone or virtually.
• Typically semi-structured with open-ended questions.
• Last anywhere from 30-90 minutes.
• Provide rich, detailed responses.
• Require skilled moderators to probe and adapt in real time.

Why are in-depth interviews important in market research?

IDIs are essential for uncovering deep insights that can’t be captured through surveys alone. They help marketers understand the “why” behind consumer behaviors, explore complex topics and inform the development of messaging, products or services.

Who relies on in-depth interviews within the marketing research and insights industry?

• Brand and product managers.
• UX and customer experience teams.
• Insights and strategy professionals.
• Health care and B2B researchers.
• Innovation and research and development teams.

How do market researchers and insights professionals use in-depth interviews?

Researchers use IDIs to explore early-stage ideas, test reactions to concepts or messaging, understand decision-making processes and develop personas. The findings are often synthesized into themes or narratives that guide strategy and innovation.