Define Hypothesis

Turns vague product ideas into testable statements with clear metrics and validation plans. You'd use this before committing resources to a feature, when your team has competing assumptions, or when setting up A/B tests. Follows the "We believe that [action] for [target user] will [outcome]" format and forces you to define specific success metrics, guardrails, and falsifiable criteria. The structured template keeps you honest about what you're actually testing. Fits into the triple diamond and lean startup frameworks if you're into that. Most useful when you're about to build something expensive based on gut feel and need to make your assumptions explicit enough that the whole team can argue about them productively.

skills.sh installs: 858
GitHub stars: 794
last updated: Aug 21, 2026

View on GitHub

Install

$ npx -y skills add product-on-purpose/pm-skills --skill define-hypothesis --agent claude-code

Installs into .claude/skills of the current project.

Files

Hypothesis

A hypothesis is a testable prediction about how a change will affect user behavior or business outcomes. It transforms assumptions into explicit statements that can be validated or invalidated through experimentation. Well-formed hypotheses prevent teams from building features based on untested beliefs and create shared understanding of what success looks like.