Hi Steve. Thanks for your reply. I've been studying a lot since I posted the question and I did learn about the mixed model being more appropriate for split-plot than the glm. I published the first year of data in the proceedings of a conference and therefore it wasn't peer reviewed. I wish it had been so I'd learn the correct way to do it. I am glad I ran into missing data problems this year in order to study again and learn the correct way. I ran my data for this year using proc glimmix this time and re-ran last year's data using glimmix as well and results are fairly similar but mean separation is a little bit different since I've used Tukey-Kramer instead of Duncan this time. By the way, I never quite understood how you pick the most appropriate mean separation test for a specific set of data. Do you have any suggestions of a good reading about it? Also, using glimmix, and I believe using proc mixed also, I need to choose a method for the calculation of the denominator degrees of freedom. I used kr as suggested by a stats person but I would like to know more about the different methods that can be used. I'd appreciate if you know any reading about that too. Thanks, Aline
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