Why You Are Probably Interviewing the Wrong People (And How to Fix It)

Teresa Torres explains how she selects participants for a product management research study that drew 90 responses in 48 hours. She argues that interviewing is qualitative and descriptive, so the statistical idea of a representative sample does not apply; instead, interviewees should be chosen for variation. Quantitative methods like surveys and A/B tests are predictive and need random, representative samples. Teams benefit by pairing qualitative insights with quantitative validation. Interviewing should continue until the same patterns and stories repeat, a point that feels uncomfortable but becomes intuitive with experience.

01Key takeaways

• Don't pick interview participants as if you were building a statistically representative survey sample.
• Select interviewees deliberately for variation in experience, company size, and role to surface a range of behaviors.
• Study extreme users, since insights from edge cases often apply to mainstream customers too.
• Use qualitative research to generate insights, then validate them quantitatively against a larger audience.
• Keep interviewing until you hear the same patterns and stories repeatedly, accepting that the process feels ambiguous.
• Expect to over-interview early on; this is harmless and builds intuition for knowing when enough is enough.

02Key sections

Why Representative Samples Don't Fit Interviews

Torres notes that representative sampling comes from quantitative methods, which aim to predict behavior. Interviews are qualitative, so the sampling logic differs.

Descriptive vs. Predictive Research

Qualitative research describes individual experiences in depth, while quantitative research predicts attributes of a larger audience using random sampling.

Combining Qualitative and Quantitative Methods

Qualitative work generates insights, and quantitative testing checks whether those insights hold for a broader population. Starting with qualitative research avoids guesswork.

Selecting for Variation and Extreme Users

Choosing participants across company size, experience, and role reveals a wider range of experiences. Studying extreme users can surface insights that apply to everyone.

Knowing When to Stop Interviewing

Interviewing should continue until variety is covered and the same patterns recur. Uncertainty is normal, and intuition develops with practice.

03From the post

“Last Wednesday I put out this call to product managers to participate in a research study about the life of a product manager. I am overwhelmed by the response. In the first 48 hours, I have 90 responses. I was initially thinking that I would interview 9–12 people. But”

04Frameworks mentioned

Summary and takeaways written by PM Atlas; quotes are short excerpts. © the original author.