Grading on a curve
（重定向自Grading curve）
In education, grading on a curve (also referred to as curved grading, bell curving, or using grading curves) is a statistical method of assigning grades designed to yield a pre-determined distribution of grades among the students in a class. The term "curve" refers to the bell curve, the graphical representation of the probability density of the normal distribution (also called the Gaussian distribution), but this method does not necessarily use any specific frequency distribution.