Founder Glossary
What Is the Mom Test? How to Get Honest Feedback on Your Idea
The Mom Test, from Rob Fitzpatrick's book of the same name, is a set of rules for customer conversations that produce honest, useful data. The core idea: talk about their life, not your idea. Ask about specifics in the past, not hypotheticals in the future. If even your mom couldn't lie to you, you're asking the right questions.
Why the mom test matters
People lie in customer interviews. Not maliciously - they want to be nice, or they genuinely believe they'd use your product (they won't). The Mom Test gives you questions that bypass politeness and get to behavioral truth. It's the difference between 'yeah, I'd totally use that' and 'here's what I actually did last time I had this problem.'
How it works
Three rules: (1) Talk about their life instead of your idea. (2) Ask about specifics in the past instead of generics or opinions about the future. (3) Talk less, listen more. Instead of 'Would you use an app that does X?' ask 'How do you currently handle X? Walk me through the last time it happened.'
Real example
Scenario
A founder wants to build a tool for managing side projects. Instead of asking 'Would you use a side project management tool?' they ask 'Tell me about a side project you started recently. What happened with it?'
What happened
They discover that people don't need management tools - they need accountability. Every side project died because nobody else cared whether it was finished. The product becomes a side project accountability partner, not a management tool.
Common mistakes
Asking 'Would you use this?' (the answer is always yes and it means nothing)
Fishing for compliments about your idea instead of learning about their problem
Talking more than you listen (aim for 80% listening, 20% talking)
Accepting vague praise ('that's really cool') as validation
Not asking 'Why?' when someone says they tried something and stopped
Related concepts
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