The anthology focuses on German as a Second Language as an interdisciplinary field of work and research and highlights the potential of interdisciplinary orientation in order to provide a theoretical and empirical foundation and differentiation. The contributions deal with school and university studies and research projects on theoretical discourse as well as with empirical studies beyond this. In addition to general educational methods, the focus is on vocational language training for students with migration backgrounds or the professionalization of teachers in the context of diversity. Furthermore, the associated methodological challenges are examined in detail.