What is multivariate testing and when should we use it?

Product managers often face challenges in choosing the best design or copy variation, and multivariate testing offers a comprehensive solution by allowing multiple variables to be tested simultaneously, unlike A/B testing which examines one variable at a time. Multivariate testing is beneficial for product management as it provides definitive, quantitative proof of the best variation, boosting productivity and fostering a democratic design culture by testing all ideas. Although it is perceived as complex, the approach is not much more complicated than A/B testing, but it does require more care and a larger sample size, especially for products with fewer users. There are various tools available for running multivariate tests on live websites, apps, prototypes, and email campaigns, with different technological approaches for each. While prototype and email testing are effective, survey-based multivariate testing is discouraged due to its lack of realistic data. Ultimately, while A/B testing is suitable for single-variable scenarios, multivariate testing is a faster and more efficient method for scenarios involving multiple variables.