```Date: Tue, 22 Feb 2005 14:48:51 -0800 Reply-To: Jason Sender: "SAS(r) Discussion" From: Jason Organization: http://groups.google.com Subject: Re: Carry-over residuals (for a newbie) Content-Type: text/plain; charset="iso-8859-1" My interest is in accounting for the variance due to the prior treatment; as I understand, this is called carry-over residual. For example with the design mentioned above (where columns are people, rows are periods, and letters are treatments): A B C C D B D C A Person 1 gets trt A, then trt C, then trt D. In the C treatment there may be carry-over from A, and in the D treatment there may be carry over from C. Obviously there is no carry-over for trt A because nothing came before it (as with B for person 2, and C for person 3). The point of assigning the first row an arbitrary category 'O' is so they can be grouped for a variance calculation. Let's say the response variables are the following: 22 11 13 14 11 16 21 13 14 The data in SAS might look like: Row Col Trt Resid Response 1 1 A O 22 1 2 B O 11 1 3 C O 13 2 1 C A 14 2 2 D B 11 2 3 B C 16 3 1 D C 21 3 2 C D 13 3 3 A B 14 So no row got deleted; I wanted to be able to account for carry-over. My question is: is this the right way to do it? Essentially I have made Carry-over a factor in my design. So I will have reduced my MSE degrees of freedom, but hopefully also reduced my MSE if carry-over has an effect. Am I approaching this the right way? >If you have random effects, why are you using PROC GLM, >instead of PROC MIXED? Can I get mixed to print out a nice ANOVA table like glm? Won't glm be the same if my design is balanced and I use the RANDOM statement? (BTW it's not the above design.) Thanks, Jason ```

Back to: Top of message | Previous page | Main SAS-L page