How to Grade on a Curve

Video Transcript

"There's two ways you can grade on a curve, generally speaking. The first way, the simpler way, is if you have a list of grades of the students in your class, let's say the highest grade is a 93, and the lowest grade is a 62. What you do is you say, ah, that wasn't a perfect test. In a perfect world, the best student in the class should have gotten 100. That's the first kind of grading curve. So you say, ok, this student needed 7 points to get 100, so I'm going to add 7 points on to every person's grade. So each grade now becomes 7 points higher. So this 62 becomes a 69. And this 93 becomes 100. So whoever does best in the class by definition is going to get 100, or a perfect score. That becomes the new 100. That's the first way to grade on a scale, on a curve. The second way to grade on curve is a frequency, is a distribution curve. A lot of times they base it on the bell curve, actually, but you can choose whatever you want. And what they'll do is, sometimes even before the semester starts, the teacher'll say, you can say, I want to have a certain amount of As, a certain amount of Bs, Cs, Ds, and Fs. And that's used for various reasons; it's used to eliminate the possibility of the course being too easy, or the test being too easy or something like that. So what would happen is, you might decide that you want 15% percent, let's say of 100 students in your class, make it easy. You want 15% to be As, so if you want 15 As, a certain amount of Bs, Cs, Ds, and maybe the school requires that there be 5% failing grade in the course. So that would be 5 out of 100 students actually get an F. So what would happen is, you would list the grades - let's say there's 100 students to make it easy. The top 15 scores would now be an A. It doesn't matter if they used to be Bs, Cs, or what. They're now As, and so on. And then the bottom 5 students, no matter what their grade was before, those five scores are now an F. And that would be grading on a distribution."