# Ab Testing > Use when designing experiments for subject lines, offers, cadences, or - Skill: `tomevault-io/ab-testing` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/ab-testing` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/ab-testing/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Marketing & Growth - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/ab-testing --- # Experimentation & A/B Testing Skill ## When to Use - Validating new subject lines or creative. - Testing segmentation hypotheses (persona vs behavior). - Optimizing cadence, timing, or automation triggers. ## Framework 1. **Hypothesis** – define expected uplift + rationale. 2. **Metric Selection** – primary (open/click/conv) + guardrails (unsubs, spam). 3. **Sample Sizing** – ensure stat significance (min 500 recipients per variant or use power calculator). 4. **Execution** – randomize, keep variants isolated, limit simultaneous tests. 5. **Analysis** – use z-test or Bayesian uplift; document learnings. ## Templates - Experiment brief (hypothesis, segments, KPI, risk guardrails). - Variant table (control vs test inputs, creative asset links, owner). - Calculator sheet for minimum detectable effect + sample size. - Post-test debrief doc capturing learnings + rollout plan. ## Experiment Ideas - Subject line vs preview text combos. - CTA placement (hero vs footer). - Personalization depth (basic vs dynamic modules). - Wait times between touches. ## Tips - Run no more than two tests per journey simultaneously. - Recycle learnings into playbooks + automation templates. - Segment results by persona to catch hidden signals. --- --- > Converted and distributed by [TomeVault](https://tomevault.io/claim/gtmagents) — claim your Tome and manage your conversions.