Students each control a move-able data point both on their individual calculators and in the projected space upfront. A linear regression is drawn for all the points in the upfront space.  As students move the values for slope, intercept and R (the coefficient of regression) are continually updated and the regression line redrawn.  By being given various challenges the class can explore the properties of regressions together.  Also the "data" from the entire class can be passed back to the individual calculators.

 All files can be downloaded here.

launch NetLogo activity (PC users only)

download regression models self-extracting archive

launch a variant of this with half-integer positions
 

Click to view an in-depth unit created for this activity.