What it is
The Mom Test is a framework for customer conversations, from Rob Fitzpatrick's book of the same name. The name is the whole idea: the rules are so foolproof that even your mom, who loves you and wants to encourage you, can't give you a false positive. Ask her "would you use my app?" and she'll say yes to make you happy. Ask the right questions and even she can't mislead you.
The core problem it solves is that most customer interviews are worthless. The second you describe your idea, people get polite, and polite feedback feels like validation while telling you nothing. The Mom Test flips every interview to be about the customer's life and past behavior, not your idea, so what you hear is fact instead of flattery.
When to use it
- Before you build anything. This is how you find out whether the problem is real without writing a line of code.
- When feedback feels suspiciously positive. If everyone loves it, you're probably pitching, not interviewing.
- Validating a problem or a beachhead. The Mom Test is how you confirm the pain is sharp enough to matter.
- Any time you're about to trust an opinion about the future. Replace it with a fact about the past.
How to apply it
- Talk about their life, not your idea. Never pitch. Ask how they handle the problem today and what it costs them. The moment you describe your idea, the truth walks out of the room.
- Ask about specific past events. "Tell me about the last time this happened" beats "would you ever," which just invites a polite guess about a hypothetical future.
- Dig for currency. Real problems cost time, money, or reputation. Ask what they have already tried and how much they have spent trying to fix it.
- Deflect compliments. "That sounds great" is not data. Thank them and steer back to what they actually did.
- Write down their exact words. Quotes reveal the job. Your tidy paraphrase hides it.
Example
Bad question: "Do you think a tool that tracks your product-market fit score is a good idea?" That invites a yes, and a yes tells you nothing. Good question: "Walk me through the last time you tried to figure out whether you had product-market fit. What did you actually do?" The second surfaces the real workflow, the tools they reached for, the spreadsheet they gave up on, and the exact moment it got painful. One is a compliment. The other is a map.
Interviews find the pattern. A survey proves it.
The Mom Test tells you who is genuinely disappointed and why. Run the Sean Ellis survey to turn that qualitative signal into a number you can track.
Measure your PMF score free → 14-day free trial · No credit cardCommon mistakes
- Pitching instead of listening. If you're talking more than the customer, you're doing it wrong.
- Asking about the future. "Would you" and "do you think" produce fiction. "When did you last" produces facts.
- Fishing for compliments. Feeling good after an interview is a warning sign, not a win.
- Not writing down exact quotes. The specific words are the data. Summaries launder out the truth.
How it connects to your PMF score
The Mom Test is how you avoid building a solution in search of a problem. Done right, it surfaces the real job your product would be hired for and hints at who would be genuinely upset to lose it, long before you've spent a build cycle. The Sean Ellis survey then quantifies at scale what your interviews revealed one conversation at a time. Interviews find the shape of the truth; the score measures it.
Measure what your interviews uncovered
PMFtracker runs the Sean Ellis survey and surfaces the patterns in the open-ended answers, so the job your Mom Test interviews found shows up in a number you can track.
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