ab-testing

Designs and analyzes A/B tests with hypothesis frameworks, sample size tables, and experiment playbooks.

1|Updated Aug 17, 2026
One-click install
npx skills add https://github.com/Marshal-Nguyen/Skill_Claude_Agent --skill ab-testing-marshal-nguyen
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: ab-testing
Source: https://github.com/Marshal-Nguyen/Skill_Claude_Agent/tree/main/claude/skills/ab-testing
Command: npx skills add https://github.com/Marshal-Nguyen/Skill_Claude_Agent --skill ab-testing-marshal-nguyen

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve? Teams often run experiments without clear hypotheses, stop tests too early, or misread statistical significance, leading to false conclusions and wasted traffic. This Skill provides a rigorous framework for planning, running, and analyzing A/B tests and building a continuous experimentation program. ## Core Features & Use Cases - Hypothesis & Test Design: Structures hypotheses with the observation-belief-outcome-metric framework and selects the right test type (A/B, A/B/n, MVT, split URL) with traffic allocation guidance. - Sample Size & Duration Planning: Provides quick-reference sample size tables by baseline conversion rate and minimum detectable effect, plus duration formulas and sequential testing guidance via the references guide. - Experiment Program Management: Covers ICE prioritization, experiment velocity metrics, playbook documentation templates, and weekly-to-quarterly review cadences. - Use Case: A growth marketer wants to test a new pricing page headline. The Skill calculates that at a 3% baseline conversion rate they need roughly 31,000 visitors per variant to detect a 20% lift, defines primary and guardrail metrics, and produces a pre-launch checklist and results documentation template. ## Quick Start Ask the assistant to help design an A/B test for a specific page or change, providing your current conversion rate and traffic volume.

Frequently Asked Questions about ab-testing

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I calculate sample size for an A/B test?▼

Sample size depends on your baseline conversion rate, minimum detectable effect, significance level (95%), and power (80%). For example, a 3% baseline detecting a 20% lift needs about 31,000 visitors per variant. Use the reference tables or calculators like Evan Miller's.

How long should I run an A/B test?▼

Run until you reach the pre-calculated sample size, with a minimum of one full week to capture day-of-week variation. Avoid running longer than 4-8 weeks due to novelty effects and external factors. Never stop early based on peeking at results.

What is the difference between A/B testing and multivariate testing?▼

A/B tests compare two versions with a single change, while multivariate tests (MVT) test combinations of multiple elements simultaneously. MVT requires dramatically more traffic since combinations multiply, so sequential A/B tests are often better for lower-traffic sites.

Why is my A/B test showing significance after only a few days?▼

Early significance is often misleading due to the peeking problem, regression to the mean, and audience mix shifts. Checking results before reaching sample size inflates false positive rates. Commit to the full pre-calculated duration or use sequential testing methods.

What metrics should I track in an A/B test?▼

Define three tiers: one primary metric tied to your hypothesis, secondary metrics that explain why the change worked, and guardrail metrics that should not get worse. For a signup form test, completion rate is primary while lead quality is secondary.

When should I not run an A/B test?▼

Skip testing when traffic cannot support detecting a meaningful effect within a reasonable duration, when the change is too small to detect, or when qualitative research answers the question faster. Alternatives include increasing the MDE, testing upstream pages, or deciding from user research.