This report presents a systematic review of empirical research published internationally between 1990 and 2008 on the relationship between factors in primary and lower secondary schools (input and process) and pupils’ learning (output and outcome). The project was commissioned by the Danish Evaluation Institute (Danmarks Evalueringsinstitut) and was performed on behalf of the Nordic Indicator Workgroup (DNI). DNI is a workgroup nominated by the Nordic Evaluation Network, which consists of representatives of The Agency for the Evaluation and Quality Development of Primary and Lower Secondary Education in Denmark, the Danish Evaluation Institute, the Swedish National Agency for Education, the Norwegian Directorate for Education and Training, the Finnish National Board of Education and the Ministry of Education, Science and Culture in Iceland. The project was carried out in the period 1.10.2008-15.01.2010.