Hello,
I have a Strip-Split-Plot design with SAMPLING on the lowest plot. I already have done hard work researching and did not get final conclusion if I even must use a subsample error term and if what is correct error for the sub-sampling in these design.
I wrote the code below, and would be great full if someone could help me suggestim a better one.
PlotA=main plot, and within each PlotA I have a strip-plot with Row factor and Col factor. (With SUBSAMPLING)
PROC GLIMMIX data=dataset plots=studentpanel;
Class Block PlotA Row Col;
Model Y=PlotA | Row | Col / ddfm=satterthwait;
Random Block(PlotA) Row*Block(PlotA) Col*Block(PlotA) Row*Col*Block(PlotA);
run;
Thank you.
If by "randomized complete block (RCB) with Factor 'A' with 'a' levels", you mean that each level of A is applied to a whole plot (identified as "Block*A") within each block--in other words, you have 'a' whole plots in each block--and that the row strips and the column strips are entirely contained within each whole plot, then ideally you would want
random block
block*a
block*row
block*a*row
block*col
block*a*col
block*row*col
block*a*row*col;
Lots of variance estimates! So the full list of terms might not be feasible.
Your original RANDOM statement would be correct if levels of factor A were randomly assigned to blocks rather than whole plots within blocks.
Susan
Thanks Steve Denham
I checked the link and I believe that my code is correct.
Since I have a strip-plot within a simple randomize complete block (RCB) with Factor 'A' with ''a' levels, the interraction 'Block*A' become the "blocks" for the strip-plot, is it OK?
Thank you
That sounds correct, and also sounds a lot like an example in SAS for Mixed Models, 2nd ed., where an extensive strip plot example is worked out.
Steve Denham
If by "randomized complete block (RCB) with Factor 'A' with 'a' levels", you mean that each level of A is applied to a whole plot (identified as "Block*A") within each block--in other words, you have 'a' whole plots in each block--and that the row strips and the column strips are entirely contained within each whole plot, then ideally you would want
random block
block*a
block*row
block*a*row
block*col
block*a*col
block*row*col
block*a*row*col;
Lots of variance estimates! So the full list of terms might not be feasible.
Your original RANDOM statement would be correct if levels of factor A were randomly assigned to blocks rather than whole plots within blocks.
Susan
Susan is right--I read it as a split-split plot, not a strip-split plot. Mark her answer as correct.
Steve Denham
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