Devoted to images that illustrate statistical ideas
Monday, November 11, 2013
Top of the Heap? Mediocre Still
Here is a cartoon from Rhymes with Orange. A student looking at a bell-curve of SAT scores says, "My strategy? Shoot for the top of the bell curve. Then I can look down on everybody." The student clearly has the wrong idea. He seems to think that the peak of the bell curve puts him on the top of the heap. For him, higher on the curve is better than everyone. This mistake we've seen before in this blog here and here. But just perhaps the cartoonist, Hilary Price, has the idea of the bell curve correct. She shades in the letter C on the side. Rather than seeing this as an illustration of the student's multiple choice answer to an SAT question we could imagine that she has assigned to the student a score of C, a traditional average grade, that would be the most common or the most likely grade. This is exactly what the height of the bell-curve represents for such a mid-range grade. The bell curve is tallest for the most commonly occurring grades, not for the highest grade one might strive for. That grade is at the extreme right, where the curve is low. As we've seen before the "Top of the heap is mediocre."