When should multivariate testing be selected over A/B testing?

Multivariate testing should be selected over A/B testing when you want to test multiple elements on a webpage or piece of content simultaneously to determine which combination of elements performs best. While A/B testing is suitable for testing one variable at a time, multivariate testing allows you to test multiple variables and their interactions, providing insights into how different elements affect each other. For example, if you want to test different headlines, images, and calls-to-action on a landing page, multivariate testing would be more efficient than running multiple A/B tests. However, multivariate testing requires a larger sample size to achieve statistically significant results.