The initial idea for this special issue was developed as a result of the meetings of the Educational Improvement and Quality Assurance network, of EERA/ ECER (European Educational Research Association / European Conference on Educational Research) which took place during the annual conferences in Dublin (2016) and in Copenhagen (2017). The main aims of the network are to stimulate scientific research and academic discourse on the definition, structure, implementation, assessment and impact of educational improvement and quality. Studies related to this network may refer mainly to schools but also to other formal or non-formal educational institutions, to supra-national or international organizations, and to informal initiatives that promote or affect education.