Hi, does anyone know which of the scaled or unscaled version of the variance-covariance matrix of regression coefficients (as produced by ls.diag) is the correct one, or when one is better than the other? I am interested in univariate linear regression (lm). Thank you very much. Dipl.-Psych. Johannes Ullrich Philipps-Universit?t Marburg Fachbereich Psychologie AG Sozialpsychologie 35037 Marburg Germany T. ++49 6421 / 2823654 F. ++49 6421 / 2823789