Validate before you build. This framework breaks down validation into 4 concrete stages with specific success metrics for each. Used by YC companies and lean startups worldwide.
The 4-Stage Validation Framework
Proper validation happens in stages. Each stage builds on the previous one, gradually reducing risk and increasing confidence in your idea.
Stage 1: Problem Validation
Before building anything, confirm that the problem is real, urgent, and widespread.
Validation Criteria:
- Frequency: Problem occurs weekly or more often
- Pain Level: Customers rate it 8+ out of 10
- Current Solutions: Existing solutions are inadequate
- Willingness to Pay: Customers currently spending money on workarounds
Success Metric:
At least 20 out of 30 interviews confirm the problem is severe and frequent. If fewer than 15 confirm, pivot or abandon.
Stage 2: Market Validation
Determine if the market is large enough to support a viable business. Calculate your TAM, SAM, and SOM.
Market Size Calculations:
- TAM (Total Addressable Market): Total market demand if you had 100% market share
- SAM (Serviceable Addressable Market): Portion you can reach with your channels
- SOM (Serviceable Obtainable Market): Realistic market share in 3-5 years
Minimum Viable Market: Your SOM should be at least $10-20M for VC-backed startups, or $1-2M for bootstrapped businesses.
Stage 3: Solution Validation
Test if your specific solution resonates before building. Use landing pages, prototypes, and pre-sales.
Testing Methods:
- Landing Page Test: 2-5% conversion to waitlist (run 1000+ visitors)
- Prototype Interviews: 70%+ positive feedback on mockups/Figma
- Pre-Sales: 10-20 customers willing to pay in advance
- Concierge MVP: Manually deliver service to first 10 customers
Stage 4: Willingness-to-Pay Validation
The ultimate test: will people actually pay? This is where most ideas fail or succeed.
Pricing Validation:
- B2B SaaS: Get 3-5 LOIs (letters of intent) with specific pricing
- Consumer: 10%+ conversion to paid (after free trial)
- Marketplace: 30%+ take rate or transaction volume targets
The Mom Test: Interview Framework
Named after Rob Fitzpatrick's book, this framework ensures you get real insights, not false validation.
Good Questions (Past Behavior):
- "Tell me about the last time you experienced [problem]"
- "What did you do to solve it?"
- "How much did that cost you?"
- "What didn't work about that solution?"
Bad Questions (Hypothetical):
- "Would you use a product that does X?"
- "How much would you pay for X?"
- "Do you think this is a good idea?"
