Regression by eye
The applet below allows one to interactively estimate the regression
line for a data set. When the applet loads, a data set consisting of
20 points is displayed. Points can be added to the plot by clicking
the mouse. Points on the plot can be removed by clicking on the point
and then dragging the point into the trash can. All of the points on
the plot can be removed by simply clicking inside the trash can. Move
the green line on the plot by clicking and dragging the mouse over the
end points. Try to move the line in order to minimize the sum of
square error (SSE). Note that the regression line minimizes SSE. The
SSE for the green line and for the regression line are given below the
plot. The equations of each line are given above the plot. Click the
Show regression line! button to see the regression line in the
plot. Click the New data button to generate a new data set.
Things to try with the applet: