We conducted supplementary analyses to ensure that outliers did not unduly impact residual results. We identified outliers using studentized deleted residuals. To begin with, we dropped institutions with studentized deleted residuals that were greater than |3.0|, and reran the regression models. Institutional residuals did not shift appreciably after outlier schools were dropped. To check the stability of the residuals with a more inclusive cut-off for outliers, we dropped institutions with studentized deleted residuals greater than |2.25|. As with the more stringent cutoff, institutional residuals did not shift appreciably when this larger group of outliers was removed. Therefore, each Institutional Engagement Index report is based on an analysis of all institutions in the 2001-2003 National Norms.