A/B Testing Laboratory

Create comprehensive A/B testing framework for [company] email program. Test: subject line formulas (15 variants), preview text optimization, sender name variations, send time experiments, design layouts (3 templates), CTA button variations (copy, color, placement), personalization depth levels, image vs. text ratios, email length optimization, and urgency/scarcity tactics. Provide testing calendar, sample size calculator, statistical significance thresholds, and results documentation template.