This volume makes an important contribution to the discussion on the professionalization of staff in educational institutions and its empirical foundation. The individual chapters illuminate areas of competence related to pedagogical professionalism in their various facets, such as subject-specific diagnostic competencies and teaching competencies, field-specific expertise, and understanding of science, while also presenting ways to optimize these areas. Researchers from the field of education, subject didactics, and psychology within the Freiburg Competence Network for Empirical Educational and Instructional Research (KEBU) examine, in interdisciplinary teams, the subject-related competencies of teachers and educators in the mathematical and natural sciences regarding their structure and conditions of emergence.