Multilevel models are widely used in education and social science research. However, the effects of omitting levels of the hierarchy on the variance decomposition and the clustering effects have not been well documented. This paper discusses how omitting one level in three-level models affects...

Meta-analytic methods have been widely applied to education, medicine, and the social sciences. Much of meta-analytic data are hierarchically structured since effect size estimates are nested within studies, and in turn studies can be nested within level-3 units such as laboratories or...

Cultural diversity – in various forms – has in recent years turned into a prominent and relevant research and policy issue. There is an avalanche of studies across many disciplines that measure and analyse cultural diversity and its impacts. Based on different perspectives and features of...