RE: GAM analysis and further action

From: Mark Sale - Next Level Solutions mark@nextlevelsolns.com Subject: RE: [NMusers] GAM analysis and further action Date: Wed, 29 Mar 2006 12:16:37 -0700 Mats, Toufigh, I have, in general been unimpressed with both the sensitivity and specificiy of plots of post-hoc etas vs potential covariates. So, I would add your first "test" (plots) to Mats' list of things that are at best, a guide on what to try. I will, once again, suggest that the complexities of the interdependencies of covariate relationships (and interdependencies of structural effects) are a violation of the assumptions on which the post-hoc-vs-covariate plot modeling approach -and the step wise modeling approach, is based. As such, we need to reasses the basic tenets of how we select models. I'm not sure about what assumptions underlie that GAM approach. Still looking for collaborators for a formal assessment of traditional|GAM|WAM|GA model selection strategy - anyone interested? Mark Sale MD Next Level Solutions, LLC www.NextLevelSolns.com