| name | ads-test |
| description | A/B test design and experiment planning for paid advertising. Structured hypothesis framework, statistical significance calculator, test duration estimator, sample size calculator, and platform-specific experiment setup guides (Meta Experiments, Google Experiments, LinkedIn A/B). Use when user says A/B test, split test, experiment design, test hypothesis, statistical significance, sample size, or test duration. |
| user-invokable | false |
A/B Test Design & Experiment Planning
Concept adapted from OpenClaudia/openclaudia-skills (ab-test-setup).
Process
- Understand what the user wants to test (creative, audience, bidding, landing page)
- Build structured hypothesis using the framework below
- Calculate required sample size and estimated duration
- Recommend platform-specific test setup
- Define success criteria and measurement plan
Hypothesis Framework
Every test must start with a structured hypothesis:
IF we [change/action]
THEN [metric] will [increase/decrease] by [estimated %]
BECAUSE [reasoning based on data or insight]
Example:
IF we replace polished product shots with UGC creator videos
THEN Meta CTR will increase by 25-40%
BECAUSE Andromeda prioritizes diverse creative formats and UGC consistently outperforms polished in 2025-2026 benchmarks
Hypothesis Quality Checklist
Statistical Significance Calculator
Required Sample Size (per variant):
n = (Z_alpha + Z_beta)^2 × 2 × p × (1-p) / MDE^2
Where:
- Z_alpha = 1.96 (for 95% confidence)
- Z_beta = 0.84 (for 80% power)
- p = baseline conversion rate
- MDE = minimum detectable effect (relative %)
Simplified lookup:
| Baseline CVR | 5% MDE | 10% MDE | 20% MDE | 30% MDE |
|---|
| 1% | 612,000 | 153,000 | 38,300 | 17,000 |
| 2% | 302,400 | 75,600 | 18,900 | 8,400 |
| 5% | 116,800 | 29,200 | 7,300 | 3,200 |
| 10% | 55,200 | 13,800 | 3,450 | 1,530 |
| 20% | 24,600 | 6,150 | 1,540 | 680 |
Per variant, 95% confidence, 80% power
Test Duration Estimator
Duration = Required Sample Size / Daily Traffic per Variant
Minimum duration: 7 days (capture weekly patterns)
Maximum recommended: 28 days (avoid seasonal drift)
Learning phase: Google 7-14 days, Meta 3-7 days, LinkedIn 7-14 days
Inputs needed:
- Daily impressions or clicks
- Number of variants (2 = A/B, 3+ = multivariate)
- Baseline conversion rate
- Minimum detectable effect desired
Duration Quick Estimates
| Daily Clicks | 2% CVR, 20% MDE | 5% CVR, 20% MDE | 10% CVR, 20% MDE |
|---|
| 100 | 189 days | 73 days | 35 days |
| 500 | 38 days | 15 days | 7 days |
| 1,000 | 19 days | 7 days | 4 days* |
| 5,000 | 4 days* | 2 days* | 1 day* |
*Minimum 7 days recommended regardless of sample sufficiency
Platform-Specific Test Setup
Meta Experiments
- Use Ads Manager > Experiments tab (not manual ad set duplication)
- Automatic audience splitting ensures no overlap
- Supported test types: A/B (creative, audience, placement), Holdout, Brand Survey
- Meta's Incremental Attribution (April 2025) provides AI-powered holdout testing for measuring real causal impact
- Budget: split evenly across variants; minimum $100/day per variant recommended
- Duration: 7-14 days typical; Meta auto-determines winner at 95% confidence
Google Experiments
- Campaign Experiments (custom experiments) or Ad Variations
- Create experiment from existing campaign > select experiment type
- Traffic split: 50/50 recommended for fastest results
- Supported: bidding strategy, ad copy, landing page, audience
- Metrics: choose primary metric (conversions, CPA, ROAS) before launch
- Duration: 14-30 days recommended; minimum 2 weeks for bidding tests
LinkedIn A/B Testing
- Built into Campaign Manager for Sponsored Content
- Duplicate ad set with single variable change
- Target: same audience segment with automatic rotation
- Minimum budget: $50/day per variant
- Key metrics: CTR (>0.44% benchmark), CPL, Lead Form CVR (13% benchmark)
- Duration: 14-21 days (LinkedIn's smaller daily volumes require longer tests)
TikTok Split Testing
- Available in TikTok Ads Manager > Create A/B Test
- Test types: targeting, bidding, creative
- Auto-splits audience to avoid contamination
- Minimum 7 days, recommended 14 days
- Budget: minimum $20/day per ad group
- Creative tests: isolate hook (first 2-3 seconds) as the primary variable
- TikTok's enhanced split testing supports modular test variables (targeting, creative, budget, placement) via Smart+ since 2025
What to Test (Priority Order)
High Impact (test first)
- Creative concept (different messaging angles, not just color changes)
- Hook/first 3 seconds (video opening on Meta, TikTok, YouTube)
- Offer structure (pricing, discount type, free trial length)
- Landing page (headline, CTA, form length)
- Bidding strategy (tCPA vs tROAS vs Maximize Conversions)
Medium Impact
- Audience targeting (interest vs lookalike vs broad)
- Ad format (static vs video vs carousel)
- CTA button (Learn More vs Sign Up vs Shop Now)
- Campaign structure (CBO vs ABO, consolidated vs segmented)
Low Impact (test last)
- Ad scheduling (time of day, day of week)
- Device targeting (mobile vs desktop)
- Minor copy variations (word substitutions without concept change)
Common Testing Mistakes to Avoid
- Testing too many variables at once (no clear winner attribution)
- Ending tests too early (before statistical significance)
- Testing during atypical periods (holidays, launches, incidents)
- Comparing unequal time periods
- Not documenting learnings (build institutional knowledge)
- Testing small changes when big changes are needed (optimize vs innovate)
- Ignoring learning phase on automated platforms
Output Format
## A/B Test Plan
### Hypothesis
IF [change]
THEN [metric] will [direction] by [amount]
BECAUSE [reasoning]
### Test Design
| Parameter | Value |
|-----------|-------|
| Platform | [platform] |
| Test Type | [A/B / Multivariate] |
| Variable | [what's being changed] |
| Control | [current state] |
| Variant | [proposed change] |
| Primary Metric | [KPI] |
| Traffic Split | [50/50 / other] |
### Sample Size & Duration
| Metric | Value |
|--------|-------|
| Baseline CVR | [X%] |
| MDE | [X%] |
| Required Sample | [N per variant] |
| Daily Traffic | [N clicks/day] |
| Est. Duration | [X days] |
| Min Duration | 7 days |
### Success Criteria
- Winner declared at 95% confidence
- [Primary metric] improvement of [X%]+ sustained over [Y] days
- No negative impact on [secondary metric]
### Setup Instructions
[Platform-specific step-by-step]
