Generate Evidence
Build the evidence. Do not fill the gap with narrative.
ProductBooks tools exist to generate missing proof for the stage you are trying to pass.
Use tools after a stage shows what still scores zero.
Use tools by stage
Generate the missing input, then re-run the evaluator for the same stage.
Problem–Solution Fit
- If the problem is weak, every signal above it misleads.
- Generate evidence for problem before moving up.
Product–Market Fit
- If users do not return, you do not have product–market fit.
- Generate evidence for product before moving up.
Business Model Fit
- If margins break at scale, the model fails.
- Generate evidence for business model before moving up.
Problem stage tools
Use these to generate scoreable inputs for Problem–Solution Fit.
User Survey Generator
GENERATEDesign behaviour-based surveys that reveal real problems, frequency, and current alternatives.
Used to improve
Problem–Solution Fit: Problem existence, frequency evidence
User Interview Generator
GENERATECreate structured interviews that uncover real pain, past behaviour, and failed solutions.
Used to improve
Problem–Solution Fit: Observed problem intensity and user context
Prototype Test Generator
BUILDTest real user reactions to your solution without explanation or selling.
Used to improve
Problem–Solution Fit: Solution reaction and behavioural validation
How to use them
Keep the flow strict. Tools improve evidence. They do not replace evaluation.
Run the loop in order
- Run the evaluator first.
- Identify what still fails or scores zero.
- Generate evidence for that exact gap.
- Re-run the evaluator before moving stages.
What to do next
Most teams should run Problem–Solution Fit before using any tool.
The evaluator tells you which evidence is missing. The tool should answer that gap, not create more noise.
Go to Problem–Solution FitGenerate evidence only after the stage tells you what is missing.
Start with the evaluator, then use the right tool to improve the next re-run.