# Computer Game #1   ---  Regression by Eye

## Instructions

A "Begin" button will appear at the bottom of this file when the applet is finished loading. This may take a minute or two depending on the speed of your internet connection and computer. Please be patient. If no begin button appears, it is probably because your browser does not support Java 1.1.

Starting the Applet and setting the conditions
Press the "Begin" button to start the applet in another window.

This applet lets you estimate the regression line and to guess the value of Pearson's correlation.

1.      Select the "Show minimum MSE" option. The mean square error (MSE) is the average squared deviation of points from the line.

2.      Indicate your estimate of the regression line by drawing a line on the scatterplot. When you release the mouse button the MSE from the line you drew will be displayed.

3.      You can draw another line and see if you can lower the MSE.

4.      To see the best fitting line (by the criterion of least squares) select the "Draw regression line" option.

5.      Five possible values of Pearson's correlation are listed. One of them is the correlation for the data displayed in the scatterplot. Guess which one it is.

6.      To see the correct value of Pearson's correlation, click on the "Show r" button.

7.      Click the "New Data" button to try again.

Repeat the above steps until you have (a) drawn a regression line that comes within 5 of the minimum MSE and (b) estimated the correlation correctly four times in a row.

Source: http://www.ruf.rice.edu/~lane/rvls.html