When you have determined your design and collected data, you can analyze both location and dispersion models. The following is a list of steps for analyzing location and dispersion models in Minitab, with options to consider at each step:
For example, a 23 factorial design with four repeats has eight experimental runs with four measurements per run. Minitab calculates the mean of the four repeats at each run, giving you a total of eight observations. The same design with four replicates has 32 experimental runs. In this case, each measurement is a distinct observation, giving you 32 observations. Experiments with replicate measurements have more degrees of freedom for the error term than experiments with repeats, which provide greater power to determine differences between factor settings in the location model.