Dear all, I am running these two types of commands in stata: bootstrap, reps(200): xtgee depvar indvar, fam(normal) link(id) i(case_no) t(week1_10) robust xi: xtgee depvar i.indvar, fam(normal) link(id) i(case_no) t(week1_10) vce(bootstrap, reps(200)) The two commands give similar results for some of the variables, but for some of the variables I get very different results with respect to significance, for most of the variables I get significant results with the 1st command given above. The dependent variables are of very complex nature and does not follow the assumption of normality, independent variable is a categorical(0,1) I will really appreciate if somebody could add comments/suggestions on this query. Muhammad Riaz