One of the primary goals of international large-scale assessments in education is the comparison of country means in student achievement. This article introduces a framework for discussing differential item functioning (DIF) for such mean comparisons. We compare three different linking methods: concurrent scaling based on full invariance,…

Multiple imputation (MI) can be used to address missing data at Level 2 in multilevel research. In this article, we compare joint modeling (JM) and the fully conditional specification (FCS) of MI as well as different strategies for including auxiliary variables at Level 1 using either their manifest or their latent cluster means. We show with…

This study aimed at gaining further understanding of kindergartners' performance in imaginary perspective-taking (IPT) by examining whether they can imagine "what" is visible from a particular point of view (IPT type 1: visibility) and "how" an object or scene will look from a particular point of view (IPT type 2: appearance).…