Calculating Final Course Grades: What about Dropping Scores or Offering a Replacement?

In a small study undertaken in three sections of intermediate macroeconomic theory, MacDermott compared three assessment policies in terms of their impact on the cumulative final exam score: 1) three in-class exams each worth 20 percent of the grade; 2) three in-class exams with the lowest exam score dropped and the other two exams each worth 30 percent of the grade; and 3) three in-class exams (each worth 20 percent), plus the option of an end-of-course exam  whose score is permitted to replace the lowest score on the other three exams.