The work with system constellations, which involves the spatial representation of relationships through representatives, has been a topic of ongoing controversy but has been relatively under-researched so far. At the University of Heidelberg, its effectiveness has now been examined for the first time in a randomized controlled study. The book presents the structure and results of the Heidelberg study, which surveyed over 200 participants from eight constellation seminars. After an introduction to the constellation method and a summary of existing findings on its effectiveness, the authors describe the study design and the research instruments used. In several chapters, the results of various sub-aspects are presented, including the effectiveness of constellation seminars after one year. Illustrations and tables, including statistical details, complement the presentation.