• Independent t-Test error

    From KevinB@21:1/5 to All on Wed May 27 15:10:18 2020
    First time using IBM Stats. Having trouble running independent t-test. This is the output log:

    T-TEST GROUPS=Group(1 2)
    /MISSING=LISTWISE
    /VARIABLES=Time_To_First_Rescue Total_Rescue_Doses Length_Of_Stay
    /CRITERIA=CI(.95).

    T-Test

    Warnings
    The Independent Samples table is not produced.


    Group Statistics
    Group N Mean Std. Deviation Std. Error Mean
    TTFR treatment 41 143.0807 80.12217 12.51298
    control 0a . . .
    TRD treatment 41 31.585 22.2328 3.4722
    control 0a . . .
    LoS treatment 41 20.463 3.2023 .5001
    control 0a . . .
    a t cannot be computed because at least one of the groups is empty.

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  • From Rich Ulrich@21:1/5 to behbahak@oregonstate.edu on Wed May 27 23:46:42 2020
    On Wed, 27 May 2020 15:10:18 -0700 (PDT), KevinB
    <behbahak@oregonstate.edu> wrote:

    First time using IBM Stats. Having trouble running independent t-test. This is the output log:

    It tells you, "at least one of the groups is empty."

    That is a very strong clue ....

    You have specified that the two groups are coded 1 and 2.
    (I would have put a comma between them, but that's
    probably not any problem.)

    You can do a FREQUENCIES to see how Group is coded in your data.



    T-TEST GROUPS=Group(1 2)
    /MISSING=LISTWISE
    /VARIABLES=Time_To_First_Rescue Total_Rescue_Doses Length_Of_Stay
    /CRITERIA=CI(.95).

    T-Test

    Warnings
    The Independent Samples table is not produced.


    Group Statistics
    Group N Mean Std. Deviation Std. Error Mean
    TTFR treatment 41 143.0807 80.12217 12.51298
    control 0a . . .
    TRD treatment 41 31.585 22.2328 3.4722
    control 0a . . .
    LoS treatment 41 20.463 3.2023 .5001
    control 0a . . .
    a t cannot be computed because at least one of the groups is empty.


    --
    Rich Ulrich

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