Reference table
Customer interview sample size by research type
A quick reference for how many customer interviews to plan, based on the question you are trying to answer. Pick the row that matches your goal, multiply by the number of segments where a row says per segment, and keep going until new conversations stop adding themes. With Koji, AI interviews run in parallel, so the larger ranges are practical without booking each call.
Where this appears
What's in this reference table
| Research type | Interviews | Use it for |
|---|---|---|
| Usability testing | 5 to 8 per segment | Finding task and interface problems in specific flows |
| Discovery interviews | 12 to 20 | Understanding problems, needs and current workarounds |
| Segmented research | 8 to 12 per segment | Telling real segment differences from individual variation |
| Concept validation | 15 to 25 | Testing new concepts and value propositions |
| Market research | 30 to 50+ | Broader market understanding and sizing opportunities |
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<a href="https://www.koji.so/visuals/customer-interview-sample-size-by-research-type"><img src="https://www.koji.so/visuals/customer-interview-sample-size-by-research-type/customer-interview-sample-size-by-research-type.png" alt="Table of customer interview sample sizes by research type, from 5 to 8 for usability testing to 30 to 50 or more for market research." width="1200" height="798" /></a>
<p>Source: <a href="https://www.koji.so/visuals/customer-interview-sample-size-by-research-type">Customer interview sample size by research type</a>, Koji</p>
