## Strip-Split-Plot

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Posts: 8

# Strip-Split-Plot

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.

Accepted Solutions
Solution
‎06-29-2015 03:09 PM
PROC Star
Posts: 275

## Re: Strip-Split-Plot

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

All Replies
Posts: 2,655

## Re: Strip-Split-Plot

See this thread for a strip-split plot model

Steve Denham

Occasional Contributor
Posts: 8

## Re: Strip-Split-Plot

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

Posts: 2,655

## Re: Strip-Split-Plot

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

Solution
‎06-29-2015 03:09 PM
PROC Star
Posts: 275

## Re: Strip-Split-Plot

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

Posts: 2,655

## Re: Strip-Split-Plot

Susan is right--I read it as a split-split plot, not a strip-split plot.  Mark her answer as correct.

Steve Denham

🔒 This topic is solved and locked.