The purpose of multivariate testing is to simultaneously gather information about multiple variables and then conduct an analysis of the data to determine which recipe results in the best performance.
Multivariate testing approaches differ on two important dimensions:
The data can be collected in a full factorial or fractional factorial fashion (see the “Data Collection” section that follows). The subsequent analysis can be either parametric or nonparametric (see the “Data Analysis” section later in this chapter). Within parametric analysis there are also significant differences. Some forms of parametric analysis take complex variable interactions into account, and others ...