Problem Note 37759: PROC GLM incorrectly reports pvalues with the PDIFF option for LSMEANS involving a constant dependent variable
If you have a constant dependent variable when using PROC GLM and request the PDIFF option on the LSMEANS statement, then the p-values for the comparisons are incorrectly reported as 1.000. Prior to SAS 9.2 the p-value was incorrectly reported as <0.0001. The correct p-value should be set to missing since there is no estimate for the associated standard error.
To circumvent the problem, either write an ESTIMATE statement in PROC GLM or use PROC MIXED.
Operating System and Release Information
| SAS System | SAS/STAT | z/OS | 9.1 TS1M3 SP4 | 9.2 TS2M3 |
| Microsoft® Windows® for 64-Bit Itanium-based Systems | 9.1 TS1M3 SP4 | 9.2 TS2M3 |
| Microsoft Windows Server 2003 Datacenter 64-bit Edition | 9.1 TS1M3 SP4 | 9.2 TS2M3 |
| Microsoft Windows Server 2003 Enterprise 64-bit Edition | 9.1 TS1M3 SP4 | 9.2 TS2M3 |
| Microsoft Windows XP 64-bit Edition | 9.1 TS1M3 SP4 | 9.2 TS2M3 |
| Microsoft Windows 2000 Advanced Server | 9.1 TS1M3 SP4 | |
| Microsoft Windows 2000 Datacenter Server | 9.1 TS1M3 SP4 | |
| Microsoft Windows 2000 Server | 9.1 TS1M3 SP4 | |
| Microsoft Windows 2000 Professional | 9.1 TS1M3 SP4 | |
| Microsoft Windows NT Workstation | 9.1 TS1M3 SP4 | |
| Microsoft Windows Server 2003 Datacenter Edition | 9.1 TS1M3 SP4 | 9.2 TS2M3 |
| Microsoft Windows Server 2003 Enterprise Edition | 9.1 TS1M3 SP4 | 9.2 TS2M3 |
| Microsoft Windows Server 2003 Standard Edition | 9.1 TS1M3 SP4 | 9.2 TS2M3 |
| Microsoft Windows XP Professional | 9.1 TS1M3 SP4 | 9.2 TS2M3 |
| Windows Vista | 9.1 TS1M3 SP4 | 9.2 TS2M3 |
| 64-bit Enabled AIX | 9.1 TS1M3 SP4 | 9.2 TS2M3 |
| 64-bit Enabled HP-UX | 9.1 TS1M3 SP4 | 9.2 TS2M3 |
| 64-bit Enabled Solaris | 9.1 TS1M3 SP4 | 9.2 TS2M3 |
| HP-UX IPF | 9.1 TS1M3 SP4 | 9.2 TS2M3 |
| Linux | 9.1 TS1M3 SP4 | 9.2 TS2M3 |
| Linux on Itanium | 9.1 TS1M3 SP4 | 9.2 TS2M3 |
| OpenVMS Alpha | 9.1 TS1M3 SP4 | 9.2 TS2M3 |
| Solaris for x64 | 9.1 TS1M3 SP4 | 9.2 TS2M3 |
| Tru64 UNIX | 9.1 TS1M3 SP4 | 9.2 TS2M3 |
*
For software releases that are not yet generally available, the Fixed
Release is the software release in which the problem is planned to be
fixed.
| Type: | Problem Note |
| Priority: | low |
| Topic: | Analytics ==> Analysis of Variance
SAS Reference ==> Procedures ==> GLM
|
| Date Modified: | 2009-11-09 10:12:03 |
| Date Created: | 2009-11-07 08:53:43 |
