05 September 2026
Forcing account creation at checkout costs a median 8% in completed orders vs offering guest checkout. From 6 ecommerce tests, range 4-14%, larger drop on first-time visitors. The account requirement …
04 September 2026
Multi-step checkout converts ~equal to single-page in aggregate, but wins ~7% on mobile and loses ~3% on desktop. Segment split from a 14-test pooled set; the aggregate hides the real story. Mobile us…
03 September 2026
Exit-intent surveys get ~3% response; mid-task micro-surveys get ~11% but bias the funnel they measure. Response rates from one SaaS onboarding, two placements. Exit surveys catch leavers cleanly but …
02 September 2026
Inline field validation beats on-submit modal errors by a median 4.1% form-completion uplift. Pooled across 9 form tests, fixed-effects meta-estimate, 95% CI roughly 2.0-6.2%. Inline corrects errors a…
01 September 2026
CUPED variance reduction cuts required sample by ~20-50% when pre-period data correlates with the metric. Reduction scales with correlation²; at r=0.6 you save ~36% of traffic. CUPED (controlled pre-e…
31 August 2026
A 4-factor multivariate test needs ~16x the sample of a single A/B to detect the same main effect. Combinatorics: 2^4 = 16 cells, each needing power. MDE held at 5%. MVT (multivariate testing) earns i…
