Making sense out of measurement non-invariance: how to explore differences among educational systems in international large-scale assessments

Abstract

International large-scale assessment in education aims to compare educational achievement across many countries. Differences between countries in language, culture, and education give rise to differential item functioning (DIF). For many decades, DIF has been regarded as a nuisance and a threat to validity. In this paper, we take a different stance and argue that DIF holds essential information about the differences between countries. To uncover this information, we explore the use of multivariate analysis techniques as ways to analyze DIF emphasizing visualization. PISA 2012 data are used for illustration.