Multivariate testing

Multivariate testing varies multiple elements (headline, image, CTA) at once. Reveals interaction effects but requires significant traffic.

When to use

You have enough traffic for 4-8 variants and suspect interactions between variables.

When not

Low-traffic pages where you can barely get one A/B to significance.

Analysis

Statistical models to isolate main effects and interactions. More complex than comparing two numbers.

What to do with this

• Default to A/B testing, MVT is overkill for most operators and requires traffic most don't have
• Run MVT only when you have 200K+ visitors/month and variables expected to interact (headline × image combinations)
• Reserve MVT for long-running flagship pages, short-cycle creative tests run better as sequential A/Bs
• Be prepared for longer test cycles, MVT needs 3-5x the sample size of A/B to isolate effects
• Interpret MVT results carefully, "interaction effects" between variables can lead to incorrect conclusions if not analyzed with a statistician