Discrimination in grading: A scoping review of studies on teachers' discrimination in school

Studies on teachers' grading suggest that school grades depend not only on students' performance but also on teachers' bias toward specific social categories. Numerous studies tested the existence of discrimination in grading using different strategies and focusing on multiple students' characteristics. This study aims to summarise those studies by identifying (1) the methodologies used, (2) the characteristics on which discrimination is based and (3) the empirical results. We conducted a scoping review where studies were selected blindly by the two authors. The initial search was conducted on ERIC, Education Database and PsycInfo and 37 studies were finally identified. A comparison among the included studies suggests that the main strategies used are experiments and regression analysis on the difference between blind and non-blind scores, while gender, race/ethnicity and migration background are the most frequently tested characteristics. Finally, on average studies confirmed the presence of discrimination in grading still with some exceptions and, sometimes, under specific conditions. To conclude, it is challenging to test teachers' discrimination through grading and to date the methodologies used have some limitations. However, on average, empirical evidence suggests that school grades are affected by teachers' bias.