+ Reply to Thread
Results 1 to 2 of 2

Thread: F Change Test and ANCOVA

  1. #1
    Points: 5, Level: 1
    Level completed: 9%, Points required for next Level: 45

    Posts
    1
    Thanks
    0
    Thanked 0 Times in 0 Posts

    F Change Test and ANCOVA




    Given R squared between the DV and covariant, R squared between the DV and treatment (two groups), R squared between DV and covariant treatment combined, and N, could you conduct an F change test? If so, how? Could you make any conclusions about the effect of the treatment?

  2. #2
    Super Moderator
    Points: 13,151, Level: 74
    Level completed: 76%, Points required for next Level: 99
    Dragan's Avatar
    Location
    Illinois, US
    Posts
    2,014
    Thanks
    0
    Thanked 223 Times in 192 Posts

    Re: F Change Test and ANCOVA


    Quote Originally Posted by mcamigo333 View Post
    Given R squared between the DV and covariant, R squared between the DV and treatment (two groups), R squared between DV and covariant treatment combined, and N, could you conduct an F change test? If so, how? Could you make any conclusions about the effect of the treatment?
    Yes, you can. Note that ANCOVA is a combination of ANOVA and Regression Analysis. As such, the "F change" statistic becomes nothing more than a t-statistic on the covariate (Square Root of the F-statistic) because it is based on one - degree of freedom. So, the way to handle this is look at the R-square for the full model (that includes the covariate) and then exclude the covariate from the model (ANOVA) and subsequently do the F-Change statistic on 1, and N- 2- 1 degrees of freedom.

+ Reply to Thread

           




Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts






Advertise on Talk Stats