What problem does it solve? Teams often run experiments without clear hypotheses, stop tests too early, or misread results, leading to false conclusions and wasted traffic. This Skill provides a structured framework for designing statistically valid A/B tests, calculating sample sizes, and building a continuous experimentation program. ## Core Features & Use Cases - Hypothesis-Driven Test Design: Structures every test around a formal hypothesis with defined primary, secondary, and guardrail metrics. - Sample Size & Duration Planning: Provides quick-reference tables and duration formulas so tests reach statistical significance before being called. - Growth Experimentation Program: Covers ICE prioritization, experiment velocity tracking, and a playbook format for compounding learnings across tests. - Use Case: A product team wants to test a new pricing page headline. The Skill calculates the required sample size from their baseline conversion rate, defines guardrail metrics like refund rate, warns against peeking at early results, and produces a documented test plan. ## Quick Start Ask the assistant to help design an A/B test for a specific page or feature, providing your current conversion rate and traffic volume.