centering

  1. E

    centering in Mplus

    Dear all, I try to center my variables before conducting mediation analyses using the following code under DEFINE: CENTER BDIBAS (GRANDMEAN); CENTER BDIm6 (GRANDMEAN); When I check the results, the mean of the first variable BDIbas has become zero (instead of 34), but the mean of BDIm6 is .45...
  2. L

    Interpreting scaling vs centring vs normalizing negative binomial model

    Hello, I'm a bit confused between the difference between scaling and centring in a negative binomial regression. My model looks like this: invertebrate abundance= Year +shoot count + epiphyte biomass(g) + epiphyte bio*shoot count Years: 2015, 2016 Shoot count range:1-30 Epiphyte bio...
  3. trinker

    Cenetering: Not that hard (unless you don't fully get it)

    I'm a hands on visual learner. So I read about: gran mean and group mean centering. I also read this seminal piece by Enders and Tofighi: http://www-bcf.usc.edu/~sping/PM-515/references/Enders%202007%20centering%20in%20multilevel%20analysis.pdf Now Im actually trying to work through is. Here...
  4. G

    Making metabolite samples with different volumes comparable prior to paired T-test

    Hi, I have metabolite measurements from tumor patients comparing samples from the tumor tissue (3 replicates per patient) against nearby unaffacted control tissue (again, 3 replicates per patient). Since the tumor and control data for each patient is paired and the overall measurements are...
  5. M

    Centering IVs for checking interaction effects in regression analysis

    Attention: I have just skimmed an article (Echambadi, R. and Hess, J.d. (2007) Mean-Centering Does Not Alleviate Collinearity Problems in Moderated Multiple Regression Models, Marketing Science 26 (3), 438-445) which clearly states that the centering of the IVs does not impact the results of a...