Run user interviews that surface real problems, not polite lies. Most interviews fail because the interviewer pitches their idea and asks "would you use this?" The Mom Test (Rob Fitzpatrick) fixes this: talk about their life, not your idea.
The Five Questions (Eric Migicovsky, YC)
Use these as the backbone of every interview. They work in order — each question digs deeper.
- What's the hardest part about [doing the thing you're exploring]? Opens with their pain, not your solution.
- Tell me about the last time you encountered that problem. Forces specifics. Past behavior > hypothetical opinions.
- Why was that hard? Uncovers root cause. Their first answer is usually surface-level.
- What, if anything, have you done to try to solve this? Existing workarounds = real pain. No workarounds = not painful enough.
- What don't you love about the solutions you've tried? Reveals gaps in existing alternatives. This is your opportunity space.
Mom Test Rules
These rules override all default interviewing instincts:
- NEVER ask "Would you use this?" or "What would you pay?" — hypothetical questions get hypothetical answers.
- NEVER pitch your solution during the interview. The moment you pitch, you stop learning.
- ALWAYS ask about past behavior. "Tell me about the last time..." not "Would you ever..."
- Deflect compliments immediately. "That sounds great!" → "Thanks — but tell me more about how you currently handle this."
- Anchor fluff to specifics. "I always struggle with..." → "When was the last time? Walk me through it."
Follow-up Framework (Gustaf Alstromer, YC)
After the Five Questions, probe for signal strength:
- Frequency: "How often does this come up?" (Daily = strong signal)
- Workarounds: "Show me how you do it today." (Screenshots, spreadsheets, hacks = gold)
- Willingness to pay: "Have you looked for or paid for a solution?" (Spending = strongest signal)
- Emotional weight: Watch for energy shifts — frustration, sighing, storytelling. That's where the real pain lives.
Conducting the Interview
- 80% listening, 20% questioning. If you're talking more than them, you're doing it wrong.
- Take notes on exact quotes, not your interpretation.
- Seek advancement, not enthusiasm. Advancement = they give you time, reputation, or money (intro to a colleague, agree to a pilot, share their data). Enthusiasm = "sounds cool!" (worthless).
- Stop interviewing when you stop hearing new things. Usually 5-8 conversations for a focused problem space.
Guidelines
- CRITICAL: The interview is about THEIR life, not YOUR idea. If you mention your product at all, save it for the last 2 minutes.
- NEVER ask leading questions. "Don't you think X would be better?" is a pitch disguised as a question.
- ALWAYS get specific. Generalities are worthless. "Some people" → "Who?" "Sometimes" → "When was the last time?"
- NEVER end without asking: "Who else should I talk to about this?" — your best interviewees come from referrals.
- ALWAYS include a reference to
references/interview-guide-template.mdfor the full question template when building an interview guide.
*Built on The Mom Test (Rob Fitzpatrick), YC's Five Questions (Eric Migicovsky), and Gustaf Alstromer's follow-up framework. Skills from productskills.*