Use of the Normal Curve as a measure of student performance simply where students fall with respect to other students who have taken the same test. The Quartile is a division of students into four equal groups, with the students who performed the best in Quartile 4 (i.e. the top 25 percent of students), those in the high middle and low middle ranges falling in Quartiles 3 and 2, respectively, and the 25 percent of the student population with the poorest performance falling in Quartile 1.