If (my) 6 was (your) 9. Reporting heterogeneity in student evaluations of teaching
研究发现学生教学评价（SET）中报告风格的异质性至少解释了课程内评价变动的三分之一，且学生按报告风格选修课程，导致课程排名失真，质疑SET用于教师激励的有效性。
Student Evaluations of Teaching (SET) are subjective measures of student satisfaction that are often used to assess teaching quality. In this paper, we show that heterogeneity in students’ reporting styles challenges SET validity. Using administrative data that enable us to track all evaluations produced by each student, we isolate student-specific reporting scales. We show that reporting heterogeneity explains at least one third of the within-course variation in SET. We also document that students sort across elective courses according to their reporting style. As a result, the average evaluation of two otherwise identical electives can differ only because of heterogeneity in the reporting style of students attending them. Using a simulation exercise, we show that this type of sorting coupled with large sampling variability severely alter the ranking of courses within a major, calling into question the use of SET to incentivise teachers.