Journal of Applied Sciences1812-56541812-5662orgz10.3923/jas.2010.611.619MidiH.BagheriA.ImonA.H.M.R.82010108In this study, we proposed Robust Variance Inflation Factors (RVIFs) in the detection of multicollinearity due to the high leverage points or extreme outliers in the X-direction. The computation of RVIFs is based on robust coefficient determinations which we called RR^{2} (MM) and RR^{2} (GM (DRGP)). The RR^{2} (MM) is coefficient determination of high breakdown point and efficient MM-estimators whereas RR^{2} (GM (DRGP)) has been defined through an improved GM-estimators. The GM (DRGP) is a GM-estimator with the main aim as downweighting high leverage points with large residuals. It has been introduced by employing S-estimators as initial values, Diagnostic Robust Generalized Potential based on MVE (DRGP (MVE)) as initial weight function and an Iteratively Reweighted Least Squares (IRLS) has been utilized as a convergence method. The numerical results and Monte Carlo simulation study indicate that the proposed RVIFs are very resistant to the high leverage points and unable to detect the multicollinearity in the data especially RR^{2} (GM (DRGP)). Hence, this indicates that the high leverage points are the source of multicollinearity.]]>Andersen, R.,2008Bagheri, A., H. Midi and A.H.M.R. Imon,2009Bagheri, A. and H. Midi,2009Belsley, D.A., E. Kuh and R.E. Welsch,1980Chatterjee, S. and A.S. Hadi,2006Coakley, C.W. and T.P. Hettmansperger,1993Croux, C., P.J. Rousseeuw and O. Hossjer,1994Habshah, M., M.R. Norazan and A.H.M.R. Imon,2009Hadi, A.S.,1988Hair, J.F., R.E. Anderson, R.L. Tatham and W.C. Black,2006Hill, R.W.,1977Jolliffe, I.T.,1982Kamruzzaman, M. and A.H.M.R. Imon,2002Kutner, M.H., C.J. Nachtsheim and J. Neter,2004Maronna, R.A., R.D. Martin and V.J. Yohai,2006Marquardt, D.W.,1970Montgomery, D.C., E.A. Peck and G.G. Vining,2001Rousseeuw, P.J.,1984Rousseeuw, P.J.,1985Rousseeuw, P.J. and M. Hubert,1997Rousseeuw, P.J. and A.M. Leroy,2003Rousseeuw, P.J. and B.C. van Zomeren,1990Rousseeuw, P.J. and V.J. Yohai,1984Simpson, J.R.,1995Wilcox, R.R.,2005Yohai, V.J.,1987