The International Association for the Evaluation of Educational Achievement's (IEA) mission is to enhance knowledge about education systems worldwide, and to provide high-quality data that will support education reform and lead to better teaching and learning in schools. In pursuit of this aim, it conducts, and reports on, major studies of student…

This paper investigates achievement gaps between low and high socioeconomic students in 19 high-income countries. On average, math scores of students with indicators of high socioeconomic status (SES) are over one standard deviation above those with low SES indicators. The paper estimates the extent to which these achievement gaps can be…

As more primary and secondary students worldwide seek after-school tutoring in academic subjects, concerns are being raised about whether after-school tutoring can raise average test scores without widening the variability in student performance, and whether students of certain ability levels may benefit more than others from after-school…

TIMSS (Trends in International Mathematics and Science Study) is an international assessment of mathematics and science at the fourth and eighth grades that has been conducted every four years since 1995, with the most recent assessment in 2011. PIRLS (Progress in International Reading Literacy Study) is an international assessment of reading…