Modest correlations between teacher-assigned grades and external assessments of academic achievement (r = .40-.60) have led many educational stakeholders to deem grades subjective and unreliable. However, theoretical and methodological challenges, such as construct misalignment, data unavailability and sample unrepresentativeness, limit the generalisability of previous findings. We overcome these challenges by exploiting rich, population-wide data from the National Registries in Norway (n = 511,858), where state regulations require close construct alignment between grades and external exams. Correlations between lower-secondary education final grades and external exam results (r = .64-.86) suggest that grades are better measures of academic achievement than previously acknowledged. Dominance analyses and multivariate regression analyses indicate that external exam results are the best predictor of grades in the same subject. However, our results also indicate that state regulations and quality assurance systems cannot completely eradicate potential sources of discrepancy.

The Big Five personality traits play a major role in student achievement. As such, there is consistent evidence that students that are more conscientious receive better teacher-assigned grades in secondary school. However, research often does not support the claim that students that are more conscientious similarly achieve higher scores in domain-specific standardized achievement tests. Based on the Invest-and-Accrue Model, we argue that conscientiousness explains to some extent why certain students receive better grades despite similar academic accomplishments (i.e., achieving similar scores in domain-specific standardized achievement tests). Therefore, the present study examines to what extent the relationship between student personality and teacher-assigned grades consists of direct as opposed to indirect associations (via subject-specific standardized test scores). We used a representative sample of 14,710 ninth-grade students to estimate these direct and indirect pathways in mathematics and German. Structural equation models showed that test scores explained between 8 and 11% of the variance in teacher-assigned grades in mathematics and German. The Big Five personality traits in students additionally explained between 8 and 10% of the variance in grades. Finally, the personality-grade relationship consisted of direct (0.02 | β| ≤ 0.27) and indirect associations via test scores (0.01 | β| ≤ 0.07). Conscientiousness explained discrepancies between teacher-assigned grades and students\' scores in domain-specific standardized tests to a greater extent than any of the other Big Five personality traits. Our findings suggest that students that are more conscientious may invest more effort to accomplish classroom goals, but fall short of mastery.

BACKGROUND: Building on the Realistic Accuracy Model, this paper explores whether it is easier for teachers to assess the achievement of some students than others. Accordingly, we suggest that certain individual characteristics of students, such as extraversion, academic self-efficacy, and conscientiousness, may guide teachers\' evaluations of student achievement, resulting in more appropriate judgements and a stronger alignment of assigned grades with students\' actual achievement level (as measured using standardized tests).
OBJECTIVE: We examine whether extraversion, academic self-efficacy, and conscientiousness moderate the relations between teacher-assigned grades and students\' standardized test scores in mathematics.
METHODS: This study uses a representative sample of N = 5,919 seventh-grade students in Germany (48.8% girls; mean age: M = 12.5, SD = 0.62) who participated in a national, large-scale assessment focusing on students\' academic development.
METHODS: We specified structural equation models to examine the inter-relations of teacher-assigned grades with students\' standardized test scores in mathematics, Big Five personality traits, and academic self-efficacy, while controlling for students\' socioeconomic status, gender, and age.
RESULTS: The correlation between teacher-assigned grades and standardized test scores in mathematics was r = .40. Teacher-assigned grades more closely related to standardized test scores when students reported higher levels of conscientiousness (β = .05, p = .002). Students\' extraversion and academic self-efficacy did not moderate the relationship between teacher-assigned grades and standardized test scores.
CONCLUSIONS: Our findings indicate that students\' conscientiousness is a personality trait that seems to be important when it comes to how closely mathematics teachers align their grades to standardized test scores.