Wolfram Rollett is a Professor of Empirical Educational Research at the University of Education Freiburg and the Freiburg Advanced Center of Education (FACE). Previously he worked as a researcher and lecturer in the field of Educational Science and Psychology at the Universities of Potsdam, Braunschweig, Dortmund, and Wuppertal. His research focuses on school development processes, the quality of extra- and co-curricular activities, educational effectiveness, and classroom composition. After studying pedagogical and educational sciences and completing a teacher training course, Hannah Bijlsma has been working as a researcher (PhD) at the University of Twente (the Netherlands) and as a primary school teacher (grade 1). Her research focuses on measuring teaching quality and on the use of student perceptions of teaching quality in school contexts. In 2016 she founded a professional association for academic primary school teachers, of which she has been chairman for about five years. She is now a board member of the International Congress for School Effectiveness and Improvement (ICSEI) and a board member of the EARLI SIG on School Effectiveness and Improvement. After more than 10 years of working as a grammar school teacher, school development consultant, and in teacher training, Sebastian Röhl has been an academic assistant in the department of educational science at the University of Education Freiburg and is postdoctoral researcher in the Institute of Education at Tübingen University (Germany). Among other areas, he conducts research in the fields of teaching development and teacher professionalization through feedback, social networks in inclusive school classes, as well as teachers’ religiosity and its impact on professionalism. In addition, he is the director of an in-service professional master's study program for teaching and school development.