There is a common belief that the more the time students spend in the classroom the more they learn; a conception which has been supported by considerable empirical research. However, most of these studies are correlational, which does not provide solid support for their conclusions. In this research work we intend to go a step further in the…

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…