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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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2  
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
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closed as off topic by Macro, mpiktas, whuber♦ Jun 3 '12 at 18:04

Questions on Cross Validated are expected to relate to statistics within the scope defined in the FAQ. Consider editing the question or leaving comments for improvement if you believe the question can be reworded to fit within the scope. Read more about closed questions here.

1 Answer

up vote 1 down vote

You can report it to SAS, if your copy is licensed. They have a very good tech support system. Their number is 919 677 8008.

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A phone number ? I am not easy with English at phone :) – Stéphane Laurent May 3 '12 at 20:11
2  
Hi @Stephane. If you are in France, there is a French office. You can also e-mail at support@sas.com. There are offices all over the world, in fact – Peter Flom May 3 '12 at 20:16

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