Date:         Sun, 9 May 2004 09:09:48 -0400
Reply-To:     DG <digupta1@vt.edu>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         DG <digupta1@VT.EDU>
Organization: Virginia Tech, Blacksburg, Virginia, USA
Subject:      Problem with SAS code for linear contrasts

I have a 3x3x3 within subjects design. I am doing a test of linear contrast
to compare performance between cells. I want to compare 3 cells with the
rest of the 24 cells. I am using SAS to perform the linear contrast however
I end up with no values for F and p in the output.

Can someone please check my SAS code and tell me where I am going wrong. I
have pasted both my input and output.

Thanks in advance.
DG

INPUT
options pageno=1 formdlim='-';
DATA distancehypothesis;
*cell 1, 2, 3 are matched conditions (control conditions);
INPUT cell completion accuracy;
CARDS;
1 4.042 3.604
2 4.167 3.875

3 2.667 2.250

4 4.104 3.771

5 2.563 2.146

6 4.021 3.521

7 4.208 3.813

8 2.771 2.271

9 3.979 3.583

10 4.125 3.771

11 2.438 1.896

12 4.021 3.708

13 4.271 3.896

14 2.896 2.458

15 4.125 3.708

16 2.917 2.625

17 3.938 3.625

18 4.104 3.771

19 3.000 2.458

20 4.021 3.750

21 4.125 3.646

22 2.938 2.479

23 3.875 3.438

24 4.042 3.667

25 2.896 2.479

26 4.021 3.708

27 3.938 3.688

;

proc glm;

CLASS cell;

MODEL completion = cell / ss3;

contrast 'control vs treatment' cell 8 8
8 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1;

run;

OUTPUT

The SAS System 18:02 Saturday, May 8, 2004 1

The GLM Procedure

Class Level Information

Class Levels Values

cell 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
27



Number of observations 27

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The SAS System 18:02 Saturday, May 8, 2004 2

The GLM Procedure

Dependent Variable: completion

Sum of

Source DF Squares Mean Square F Value Pr > F

Model 26 10.22504874 0.39327111 . .

Error 0 0.00000000 .

Corrected Total 26 10.22504874



R-Square Coeff Var Root MSE completion Mean

1.000000 . . 3.637519



Source DF Type III SS Mean Square F Value Pr > F

cell 26 10.22504874 0.39327111 . .



Contrast DF Contrast SS Mean Square F Value Pr > F

control vs treatment 1 0.00050112 0.00050112 . .

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