Simpson's paradox in mathematics grading: A case study of Serbian primary schools

Abstract

The paper presents an empirical study that examines the academic performance in mathematics of fifteen-year-old students at the end of elementary school in Serbia. In conducting the analysis, the student results of the national test and their mathematics grades were utilized. The study covers a seven-year period 2013-19 and over 440 thousand students. Empirical findings affirm that girls exhibit superior math grades and higher achievements in national testing. However, the occurrence of Simpson’s paradox indicates a grading bias favoring girls. The results further highlight that girls exhibit a notably higher interest in attempting to solve open-ended tasks, even when unsuccessful, in contrast to boys, who leave those tasks unanswered during tests more frequently. The qualitative component of the research involved a focus group comprising teachers. It was conducted to gain insights into the teachers’ perspectives and experiences regarding the gender grading gap.