This is an extension to my previous posting about skewed covariates - but as it is a slightly different issue thought I'd start a new posting.
When running an ancova - I have a significant effect for both my between grps variable (which we will call group) - and an interaction between the covariate and grp (indicating lack of homogeneity of regression slopes). I have heard conflicting things re: interpretation i.e. should I focus solely on the interaction as this would also explain any significant main effect for group -or whether this main effect already has the covariate partialled out and so would account for some unique variance too. any help much appreciated. thanx Emma . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
