One of the most popular statistical graphs is the scatterplot which we use to visualize relationships between two quantitative variables.  Although a scatterplot is a common plot in our introductory statistics class, I think we overestimate our students’ abilities to actually understand the patterns that we’d like them to see.

I just read an interesting blog which talks about the difficulty in interpreting scatterplots.

At the graduate level, I find that students generally have difficulty in interpreting residual graphs.  It probably means that they haven’t had sufficient experience in reading residual graphs.