http://xkcd.com/1725/ This comic is another great example of allowing your student to demonstrate statistical comprehension by explaining why a comic is funny. What does the r^2 indicate? When would it be easy to guess the direction of the correlation?  More on that via this previous blog post .

When I teach regression, I usually introduce the regression line by reminding my students of the long-ago days of algebra class and graph paper and rulers. MathIsFun.com has created an interactive applet that mimics the graph paper and allows users to adjust the y-intercept and the slope . This is a slightly fancier, more high-tech way to get your students thinking about the linear equation and then fitting that old knowledge into the new concept of regression. Use the bars to adjust slope and y-intercept as a quick linear equation primer before teaching regression