To plan group-randomized trials where treatment conditions are assigned to schools, researchers need design parameters that provide information about between-school differences in outcomes as well as the amount of variance that can be explained by covariates at the student (L1) and school (L2) levels. Most previous research has offered these…

Meta-ethnography and systematic review of qualitative research are needed but also challenged by the link to the evidence movement's models and PISA-traditions for measuring learning effects. For reflections on the perspective for meta-ethnography it means to reconstruct the methodological argument almost divided in a "Before and After…

Background: The Scandinavian countries have a long history of implementing social interventions, but the interventions have not been examined using randomised controlled trials until relatively recently compared with countries like the United States and the United Kingdom. Purpose: The purpose of this paper is to examine the history of randomised…

The Programme for International Student Assessment (PISA) is an important cross-national study of 15-year-olds' academic knowledge and skills. Educationalists and public policymakers eagerly await the tri-annual results, with particular interest in whether their country has moved up or slid down the international rankings, as compared to earlier…