SPSS Statistics

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  • 1.  SPSS 28.0.0 EFA and Polychoric Correlations

    Posted Tue May 31, 2022 02:33 PM
    Hi all, 

    I'm currently using version 28.0.0 of SPSS and to try to run polychoric correlations and then EFA to validate a binary scale of 27 items. 
    According to the IBM site (R and IBM SPSS Statistics - Essentials for R), R essentials are already downloaded with SPSS and I should simply download the extensions to run my analysis (SPSSINC_HECTOR for the polychoric correlations).

    However, I can't seem to get the analysis to work despite this. I also couldn't get previous RASCH analysis which also require R to work either. Therefore, I'm assuming it's an R-related issue rather than specific to the polychoric correlations or EFA.

    I get the following error code in my output: Error: The following R package is required but could not be loaded: polycor
    SPSS HETCOR command was unable to compute the correlations due to data conditions.
    This is usually due to some variables being too far from a bivariate normal distribution.

    As I've never used R before I'm really struggling here. 

    Do I need to 'set-up' R in SPSS in any way? 
    If I don't need to enable R to run the analysis, are there any obvious solutions as to why R related analyses aren't running? 

    Any help would very very much be appreciated!

    ------------------------------
    Ailbhe Lawlor
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    #SPSSStatistics


  • 2.  RE: SPSS 28.0.0 EFA and Polychoric Correlations

    IBM Champion
    Posted Tue May 31, 2022 03:15 PM
    The R extensions are not automatically installed with Statistics.  You would need to install them via the Extensions > Extension Hub menu, but you have probably done that, since the error message is further downstream.

    The polycor package should have been installed along with HETCOR, but sometimes something prevents that from happening.

    Try running this code from a syntax window.  Be sure to select all the lines from BEGIN PROGRAM through END PROGRAM.  If the install fails, post the details you get.

    begin program r.
    install.packages("polycor")
    end program.

    or, you can install the STATS PACKAGE INSTALL extension command from the Extension Hub and then use the menu for it under Extensions.  Just enter the package name in the dialog.

    --





  • 3.  RE: SPSS 28.0.0 EFA and Polychoric Correlations

    Posted Tue May 31, 2022 03:36 PM
    Hi Jon, 

    Thank you very much for quick and understandable response! 
    I ran the code as you suggested and got the following details:


    ------------------------------
    Ailbhe Lawlor
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  • 4.  RE: SPSS 28.0.0 EFA and Polychoric Correlations

    IBM Champion
    Posted Tue May 31, 2022 03:57 PM
    It was very hard to read that error text as the type was so small, but I eventually got it.
    It was complaining that no CRAN site was specified.  Normally, the site is picked automatically or you are prompted with a pick list to choose a site.

    But try it this way (I picked an arbitrary site).
    begin program r.
    install.packages("polycor", repos="https://mirror.las.iastate.edu/CRAN/")
    end program.

    ------------------------------
    Jon Peck
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  • 5.  RE: SPSS 28.0.0 EFA and Polychoric Correlations

    Posted Tue May 31, 2022 04:24 PM
    My apologies, I (incorrectly) assumed you could expand the image!

    The new code has worked, thank you so so much!!

    ------------------------------
    Ailbhe Lawlor
    ------------------------------