To specify the design, enter the factors and replicates. You can use Power and Sample Size for General Full Factorial Design to help you to determine an appropriate number of replicates.
- Factor table
- Under Name, enter a name for each factor. Under Number of Levels, enter the number of levels for each factor.
- Number of replicates
- Select the number of replicates. Replicates are multiple experimental runs with the same factor settings (levels). One replicate is equivalent to the base design, where you conduct each run once. With two replicates, you perform each run twice (in random order), and so on.
- Block on replicates
- Select whether to put each replicate in its own block. Blocks account for the differences that might occur between runs that are performed under different conditions. For example, an engineer designs an experiment to study welding and cannot collect all of the data on the same day. Weld quality is affected by several variables that change from day-to-day that the engineer cannot control, such as relative humidity. To account for these uncontrollable variables, the engineer groups the runs performed each day into separate blocks. The blocks account for the variation from the uncontrollable variables so that these effects are not confused with the effects of the factors the engineer wants to study. For more information on how Minitab assigns runs to blocks, go to What is a block?.