SAS Institute Alert Note SN-003570

From: SAS Technical Support (LISTSERV@VM.SAS.COM)
Date: Tue Nov 14 2000 - 14:07:21 EST

  • Next message: SAS Technical Support: "SAS Institute Alert Note SN-003568"

                                     ***ALERT NOTE***
     SAS Note: SN-003570
      Product: ENT MINER
    Component: DATA.PART

    Title:
    Partition node does not work correctly with stratification

    Text:
    If you are using the Data Partition Node and also request
    Stratification, the node may not produce training, validation, and test
    data sets with the data percentages you request.

    The impact of this bug is greater when the target level of interest is
    rare.

    For example, suppose there are 10 observations out of 100,000 with
    stratification variable level A and you have requested a 70% training,
    20% validation and 10% test data set split. The Partition node should
    place 7 level A observations in the training data set, 2 in the
    validation data set, and 1 in the test data set. Because of the bug,
    these placements are not made correctly, and there is a chance that one
    or more of the partitioned data sets might not have level A at all.

    This bug occurs at random. There is no way to tell if a given scenario
    will encounter the bug or not.

    There are no notes or warnings produced. The only way that you can tell
    there is a problem would be to do a frequency analysis on the
    partitioned data sets.

    There is no circumvention.

    Keywords:
    INCORROUT INCORRSTAT PARTITION STRATIFIY STRATIFICIATION REG NEURAL TREE
    PREDICTIVE MODELING MODEL

    Reported Releases:
    +------------REPORTED------------+ +------FIXED-----+
    System Version Level Version Level

    AIX/R 4.0
    DigitUnx 4.0
    HP800 4.0
    Solaris 4.0
    WIN/NT 4.0
    Win95 4.0

    Fixes Available: None

    +-------------------------------------------------------------------------
    + NOTE: To unsubscribe you can reply to this mail with:
    + "SIGNOFF tsnews-l"
    + as the only text in the body of the message (without the double quotes).
    + If you have any questions please send them to SUPPORT@SAS.COM
    +-------------------------------------------------------------------------



    This archive was generated by hypermail 2b29 : Tue Nov 14 2000 - 15:46:53 EST