Regression Applet

The applet below is designed to teach students the effect of leverage points on a regression line. Students may add points to the plot by clicking the mouse button. Students should note that adding points close to the existing line barely changes the line. By adding points far from the existing line, the regression line changes considerably. This is particularly true for points added outside the range of the data. This should help students understand the effect of outliers on regression analysis.

by R. Webster West, Dept. of Statistics, Univ. of South Carolina
west@stat.sc.edu