Pilot-tested In-depth Interview
Also known as: pretested in-depth interview, pilot in-depth interview, pilot-tested IDI, pilot interview protocol
A pilot-tested in-depth interview is a qualitative data collection approach in which the interview guide is administered to a small number of participants before the main study, specifically to identify ambiguous questions, refine probes, estimate session duration, and verify that the protocol elicits rich, relevant narratives. The revised guide is then used in the full data collection phase, improving data quality and interview consistency.
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When to use it
Use a pilot-tested in-depth interview when your study relies on an original or significantly adapted interview guide and the quality of the data depends on participants understanding the questions as intended. It is especially valuable in sensitive topic areas, cross-cultural research, or when working with participant populations that may respond differently from the researcher's assumptions. It is also appropriate when the literature provides limited guidance on how to phrase questions about the phenomenon under investigation. Avoid treating pilot testing as optional when funding or access allows only one data collection window — investing time in piloting reduces the risk of collecting data that cannot answer the research question. Do not use the pilot sample in the main analysis unless deliberately designed as a rolling or iterative interview study.
Strengths & limitations
- Improves the validity of the interview guide by catching poorly worded or misleading questions before full data collection.
- Helps estimate realistic session duration, enabling better scheduling and participant management.
- Allows the researcher to practice interviewing skills in a low-stakes context, improving probe delivery in the main study.
- Reduces the likelihood of missing key topics by revealing gaps in the guide when tested with real participants.
- Increases methodological transparency — reporting that the guide was pilot-tested signals rigor to reviewers and readers.
- Requires access to a small number of eligible participants before the main study begins, which can be difficult in hard-to-reach or small populations.
- Adds time and cost to the data collection phase, which may be constrained in funded projects with fixed timelines.
- If the pilot reveals the need for major revisions, a second pilot round may be necessary, further extending the pre-data timeline.
- Piloting with too few individuals (fewer than two) may miss problems that only emerge with greater participant diversity.
Frequently asked
How many participants should I include in the pilot?
Two to five participants is the range most commonly recommended in the qualitative methods literature. The goal is to surface systematic problems with question wording or guide structure, not to reach data saturation. More than five pilot participants is rarely necessary unless the guide covers very diverse topic areas or multiple distinct participant sub-groups.
Can I use the pilot interview data in my main analysis?
Generally no — pilot interviews are conducted before the guide is finalized, so their data reflect a different instrument from the one used in the main study. Merging them introduces inconsistency. Some iterative or rolling interview designs explicitly plan for guide refinement across the full sample, but that is a different design that should be specified upfront, not a post-hoc justification.
Does piloting my guide count as a separate ethics approval?
This depends on your institution and jurisdiction. In many cases the pilot participants fall within the scope of the original ethics application if they share the same characteristics as the main sample. However, if pilot participants are recruited from a different setting or if data from them might be used in any way, it is safest to specify the pilot phase explicitly in your ethics submission.
What is the difference between a pilot-tested in-depth interview and cognitive interviewing?
Cognitive interviewing is a specialized pretest technique — developed primarily for survey questionnaires — in which participants think aloud or are probed about how they interpret each question. A pilot-tested in-depth interview is more naturalistic: you run the full interview as you would in the main study and observe which questions work, which produce thin answers, and how the conversation flows. Cognitive interviewing targets comprehension of specific items; pilot testing targets the guide as a whole instrument in real conversational conditions.
Is pilot testing mandatory for publication in peer-reviewed journals?
There is no universal mandate, but reporting that your interview guide was pilot-tested is increasingly expected as a quality indicator in qualitative health, social science, and education research. Major reporting standards such as COREQ (Consolidated Criteria for Reporting Qualitative Research) and SRQR (Standards for Reporting Qualitative Research) include items related to instrument development and testing.
Sources
- Kvale, S., & Brinkmann, S. (2009). InterViews: Learning the Craft of Qualitative Research Interviewing (2nd ed.). Sage. ISBN: 978-0761925422
- van Teijlingen, E., & Hundley, V. (2002). The importance of pilot studies. Nursing Standard, 16(40), 33-36. link ↗
How to cite this page
ScholarGate. (2026, June 3). Pilot-tested In-depth Interview. ScholarGate. https://scholargate.app/en/survey-methodology/pilot-tested-in-depth-interview
Which method?
Set this method beside its closest kin and read them side by side — the library lays the books on the table; the choice is yours.
- In-Depth InterviewQualitative↔ compare
- Pilot-tested Semi-structured InterviewSurvey Methodology↔ compare
- Semi-Structured InterviewQualitative↔ compare