Comparing apples and oranges: Curricular intensification reforms can change the meaning of students’ grades!

Teacher-assigned grades provide important information that is used by universities and colleges to make admission decisions and by employers to make hiring decisions. Besides grades, the results of standardized achievement tests are frequently used for student selection and allocation. However, correlations between the two achievement measures are far from perfect, and researchers have argued that this discrepancy can be at least partially attributed to norm-referenced grading, which is based on the composition of performance in a class. In this study, we investigated the results of a curricular intensification reform, which introduced changes in the distribution of student performance by making enrollment in certain courses mandatory. We investigated whether the reform resulted in changes in the relationship between standardized achievement-test results and teacher-assigned grades. We analyzed cohort control design data from two large representative samples of students from two German states (Baden-Württemberg: N = 5,574; Thuringia: N = 2,202) before and after the reform. Results indicated that students who received a certain grade before the reform (e.g., a grade of A, B, C, or D) differed in their standardized test performance from students who received the same grade after the reform. Furthermore, in math, course-level-specific reform effects on the association between grades and standardized test performance were found to vary between groups of students receiving good and poor grades. Implications for educational policy and school reforms and suggestions for grading are discussed.