DOE - Split Plot Designs: Does one ever include center points?
Mar 19, 2020 7:50 AM(291 views)
Greetings: I'm new to split plot designs, understand the basic structure and application. Does one ever include center points in such a design to detect curvature? I've searched and searched, but haven't been able to find an answer. I suspect the answer is "No", but if anyone out there can refer a document or has an answer, I'd love to know the reason.
Bruce, there would be nothing wrong with adding center points to a split-plot design. You should read "Split-plot designs for robust product experimentation", Box and Jones if you really want to take advantage of the capabilities of split-plot designs. They are NOT just for hard-to-change factors.