10-09-2013 04:13 PM
I am SAS illiterate and trying to finish my thesis (our departmental statistician retired). Having trouble collecting all necessary data for a strip-split plot. I need to analyze all of the main factors and their interactions. Previously, I was getting a minimum significant difference. Can anyone tell me if I am fully analyzing the data?
Whole plot factor: treatment
Based on information I found online and previous codes, this is what I've come up with:
proc glm data = visual;
class rep timing trt mowing;
model visual = timing|trt|mowing;
lsmeans timing|trt|mowing / pdiff adjust=BON cl lines;
10-10-2013 08:59 AM
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.