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Thread: Changing significance of variables

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    Question Changing significance of variables




    Hello,

    I have two questions regarding the significance of variables, which may sound stupid but which I don't understand. I've done some regressions in SPSS.

    First:
    I checked for the influence of IV1, IV2 and IV3 on my DV. IV1 and IV2 were significant. Then, I did another regression with IV1 and IV2 but added IV4, IV5 and IV6. Suddenly IV1 and IV2 are not significant anymore but only IV4, IV5 and IV6 are significant. What is the reason for that?

    Second:
    When operating with other variables, I did a regression wirh IVa and IVb on a DV. There was no significant influence. I know that, it makes no sense, but I tested for a moderation after that. I used PROCESS and typed in my DV from before, IVa also from before and M1 as a moderator. Besides the moderator having a significant influence, also IVa had a significant influence. How can that be?

    Thanks a lot for your answers!

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    Re: Changing significance of variables

    Hi,
    for the first question, most probably your IVs are coliniear (aka correlated).

    regards

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    Thumbs up Re: Changing significance of variables

    Thanks!

    I checked that for the first regression but forgot to check again when adding further IVs. I will check now.

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    Re: Changing significance of variables

    Can you provide output from your second example or the equation for the models you used, so that we can follow along with what you are doing.
    Stop cowardice, ban guns!

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    Re: Changing significance of variables


    When I wanted to replicate it to show you the output, it didn't occur again. Seems like I made a mistake before. Sorry. Thanks for your answers.

    Problem solved

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