How to repeat points across extremities in a custom DoE to better understand variance?
Hi!I am currently optimising an experimental procedure and have opted for a custom design with 4 continuous variables with 2 levels each and a single 3 level-categorical variable. I have included centre points (replicated) to allow for some analysis of variance and the model is generated with RSM interactions not going beyond 2 factor interactions. The residual by plots prove to be very useful but...