# To whom can we report a problem with SAS? [closed]

My question is exactly the title : to whom can we report a problem with SAS ?

Below is an example. This problem is not really severe but somewhat dangerous (in fact I have just updated my example below after Aniko's comment; there was a confusion in the first version of this post).

Consider such a dataset:

> dat
tube position           y
1     1      top  0.25602779
2     1      top  2.99327392
3     1      top  0.03673459
4     1      top -0.94515391
5     1   bottom  9.12947343
6     1   bottom  5.96666893
7     1   bottom  6.65291454
8     2      top -2.32616858
9     2      top -1.61491564
10    2      top -2.88930533
11    2      top -1.48685691
12    2   bottom  0.03474644
13    2   bottom  4.23073725
14    2   bottom  1.43776713
15    3      top  3.04525229
16    3      top -1.06611380
17    3      top  0.64097731
18    3   bottom  5.63571519
19    3   bottom  5.96779074
20    3   bottom  2.14091389
21    3   bottom  5.46937089
22    4      top  7.00724734
23    4      top  4.33632991
24    4      top  1.90765886
25    4      top  1.91688415
26    4   bottom  9.54251973
27    4   bottom  6.88220097
28    4   bottom  3.62175779
29    5      top  6.38900310
30    5      top  7.19216388
31    5      top  8.29793550
32    5   bottom  9.46722783
33    5   bottom  9.11261143
34    5   bottom 11.08097843
35    6      top -1.05244281
36    6      top -0.86450352
37    6      top -0.66251724
38    6      top -1.29278055
39    6   bottom  4.99175539
40    6   bottom  3.92459045
41    6   bottom  6.90398638


This SAS model

PROC MIXED DATA=dat ;
CLASS POSITION TUBE ;
MODEL y = POSITION / cl ;
RANDOM POSITION / type=CS subject=TUBE ;
RUN; QUIT;


is theoretically equivalent to this other SAS model (the marginal models are the same):

PROC MIXED DATA=dat ;
CLASS POSITION TUBE ;
MODEL y = POSITION / cl ;
RANDOM TUBE TUBE*POSITION;
RUN; QUIT;


However the two models yield the same estimates and standard errors but they yield completely different degrees of freedom for the estimates (with the default option).

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Have you checked out our list of SAS resources? –  whuber May 3 '12 at 20:13
I didn't know this list. Thanks ! –  Stéphane Laurent May 3 '12 at 20:20
By the way, your first SAS model should have type=CS to impose a compound symmetry structure. –  Aniko May 3 '12 at 20:26
Oops, you're right, I will do the correction. –  Stéphane Laurent May 4 '12 at 6:27
My god, I did some confusions with differents SAS codes, thanks to Aniko, I'm going to edit my post ! –  Stéphane Laurent May 4 '12 at 6:42