SAS Institute Alert Note SN-004612

From: SAS Technical Support (LISTSERV@VM.SAS.COM)
Date: Tue Apr 03 2001 - 10:36:06 EDT

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    SN-004612 ***Alert Note***

    Incorrect results are possible when the TOTAL= or N= data set is the
    same as the DATA= data set

    Product: SAS/STAT
    Component: SURVEYMEANS procedure
    Priority: ALERT

      If your sample design is stratified with different population totals in
      the strata and the totals are read into PROC SURVEYMEANS using the
      _TOTAL_ variable from the same TOTAL= or N= input data set as the DATA=
      input data set, the results will be incorrect if a class variable is
      analyzed and any strata have all missing values for that class variable.
      Either many of the computed statistics, including variances, will be
      incorrect without warning, or you may get:

         ERROR: Population total X for stratum Y in data set <data set name>
                is smaller than the sample size Z.

      when, in fact, none of your _TOTAL_ values are smaller than the sample
      size in any stratum.

      To circumvent this problem, use a different TOTAL= or N= data set than
      the DATA= data set. The TOTAL= or N= can be easily created as a copy of
      the DATA= . For example, if your DATA= data set is called ONE, then
      instead of

         proc surveymeans data=one total=one;

      do the following:

         data pop_totals;
           set one;
         run;
         proc surveymeans data=one total=pop_totals;

    Keywords:
      incorrstat incorrout totat= n= _total_ variance standard error deviation
      std class strata stratum error population total smaller than sample size
      incorrect results are possible when the total= or n= data set is the
      same as the data= data set
      004612 4612

    SAS Note Revised On: Wed, 28 Mar 2001

    System Version Reported Version Fixed

    AIX 64 bit 8.2 TS2M0
    AIX/6000 8 TSM0
    VM/ESA (CMS) 8 TSM0
    Compaq Tru64 UNIX 8 TSM0
    HP-UX Operating Systems 8 TSM0
    HP-UX 64 bit 8.2 TS2M0
    Intel ABI 8 TSM0
    Linux 8.2 TS2M0
    MIPS ABI 8 TSM0
    OS/390 (MVS) 8 TSM0
    IBM OS/2 8 TSM0
    Solaris 8 TSM0
    Solaris 64 bit 8.2 TS2M0
    OpenVMS VAX 8 TSM0
    OpenVMS Alpha 8 TSM0
    Windows NT 8 TSM0
    Windows 2000 Datacenter Server 8 TSM0
    Windows 2000 Professional 8 TSM0
    Windows 2000 Server and Advanced Server 8 TSM0
    Windows 95 8 TSM0
    Windows 98 8 TSM0
    Windows ME 8.2 TS2M0

    No Fixes Available

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