The Paderborn method is a proposed method for teaching foreign languages, originally conceived for children's education. It consists of first teaching a student a simple language (usually Esperanto) for two years, then teaching them a second language for several years after that. The time spent studying Esperanto helps the student acquire the second language more quickly, such that they end up more proficient in the second language than if they had spent the first two years studying it instead of Esperanto.
The most comprehensive experiment on the Paderborn method was done by Prof. Helmar Frank, of the University of Paderborn's Institute of Pedagogic Cybernetics, from which the method gets its name.