Nearly 50 authors enlarge the empirical base of psychodrama. The aim and research questions cover instruments, methods, and social network as well as clinical investigations of children, youth and adults. The last chapter deals with research on supervision, education and training. The contributors used mostly quantitative and mixed-method and some qualitative designs. This ends up in evaluated tools, quality development in treatment, efficacy in supervision, effectiveness in education and training. Some studies were exploratory others more rigorous and gold standard . Half of the special issue is written in English or German. Most of the authors come from Germany and Austria, but also from non German speaking countries in Europe, Asia, Australia and America.