Using Mixed Models > Generalized Linear in SPSS, I am trying to analyze data over Time (repeated measures of the same subjects monthly, from 4-12 months), Genotype (+/+, +/-, -/-), and Treatment (treated, control). Currently, I have my target (Test_Score and a gamma distribution), fixed effects (Time, Treatment, Genotype, and subsequent 2- and 3-way interactions), random effects (Subject_id) set up in the "Fields and Effects" tab.
I am confused though as to how to properly set up the "Data Structure" tab. All of the tutorials I've found suggest a hierarchy when dragging variables into the "subject" canvas (ie different hospitals or schools) but Genotype and Treatment are equally important and not nested in that way. Should I be dragging anything other than Subject_id to the "subject" canvas and Time into the "repeated measures" canvas? If so, does the order (Genotype then Treatment or Treatment then Genotype) matter?