Stop. PROC GLM will not correctly calculate standard errors for split plot models. Do whatever it takes to get a copy of Littell et al.'s SAS for Mixed Models, 2nd ed., and go to chapter 4 on split-plot models. Also check out Chapter 16, which has case studies, especially 16.4 A Split-Plot Experiment with Correlated Whole Plots, 16.5 A Complex Split Plot: Whole Plot Conducted as an Incomplete Latin Square, and 16.6 A Complex Strip-Split-Split Plot Example. Try rewriting your model using PROC MIXED. If you have problems, please post your code and the problems you are having. Good luck. Steve Denham
... View more
