The influence of school size, leadership, evaluation, and time on student outcomes: four reviews and meta-analyses

School effectiveness research addresses the question why and how some schools are more effective than others when the differences in achievement cannot be attributed to student intake and educational background characteristics. A main aim is to identify and investigate those malleable conditions at different levels –classroom, school and above school– that can directly or indirectly explain the differences in the learning outcomes of students. As from the early phases of school effectiveness research there was a great interest in reviews and later also meta-analyses that compile the start-of the art knowledge and show evidence on factors that are associated with better student achievement. The dissertation builds on these previous reviews and meta-analyses and it consists of four reviews and meta-analyses of effectiveness enhancing factors at school and/or classroom level: school size, school leadership, evaluation and assessment and time and homework. Depending on the data available in the primary studies, different methods for review and meta-analysis were applied. The meta-analyses yielded small positive significant effects for school leadership, evaluation and learning time and homework. The meta-analyses did not indicate a significant effect of assessment on student learning. For school size it was found that the impact of size varied with the type if outcome variable considered. Effects of smaller schools appeared to be stronger when social cohesion and participation were the outcome variables, while for safety and attendance the available evidence favoring small schools appeared to be less convincing. School size did not seem to matter for academic achievement. The results of this dissertation study further validate the consensus that consists of the ‘factors that work’ in education. At the same it also draws the attention to the divergence in the magnitudes in mean effect sizes that various meta-analyses yield when the same effectiveness enhancing factor is considered and provides insight into the many methodological and conceptual challenges in meta-analysis and school effectiveness research