The aim of Multi-DES is to investigate systematic design parameters and assessment measures of intervention studies in education in the multi-level context of the German school system. The research results are intended to contribute to the evidence base in education.

For the first time, design parameters and assessment measures are examined in a multi-level context in the german school system.
This is done in four studies based on representative data from three longitudinal large-scale assessment studies conducted in Germany: The National Educational Panel Study (NEPS), the national extension of the international PISA 2003 study (PISA-I+), and the DESI study (Assessment of Student Achievements in German and English as a Foreign Language).

• Study 1 examines design parameters for cluster-randomized studies for the general student population and for different school types.
• Study 2 analyzes the extent to which different covariates improve the statistical power and estimation accuracy of cluster-randomized studies.
• Study 3 examines average skill growth as an assessment measure of effect sizes for the general student population and separately by school type.
• Study 4 looks at differences in competency between low-performing and average schools as an assessment measure.