In the field of pedagogy, learning by teaching (German: Lernen durch Lehren, short LdL) is a method of teaching in which students are made to learn material and prepare lessons to teach it to the other students. There is a strong emphasis on acquisition of life skills along with the subject matter. This method was originally defined by Jean-Pol Martin in the 1980s. Background The method of having students teach other students has been present since antiquity. Most often this was due to lack of resources. For example, the Monitorial System was an education method that became popular on a global scale during the early 19th century. It was developed in parallel by Scotsman Andrew Bell who had worked in Madras and Joseph Lancaster who worked in London; each attempted to educate masses of poor children with scant resources by having older children teach younger children what they had already learned. Systematic research into intentionally improving education, by having students learn by teaching began in the middle of the 20th century. In the early 1980s, Jean-Pol Martin systematically developed the concept of having students teach other in the context of learning French as a foreign language, and he gave it a theoretical background in numerous publications. The method was originally resisted, as the German educational system generally emphasized discipline and rote learning. However the method became widely used in Germany in secondary education, and in the 1990s it was further formalized and began to be used in universities as well. By 2008 Martin had retired, and although he remained active Joachim Grzega took the lead in developing and promulgating LdL. LdL-Method After preparation by the teacher, students become responsible for their own learning and teaching. The new material is divided into small units and student groups of not more than three people are formed. Students are then encouraged to experiment to find ways to teach the material to the others. Along with ensuring that students learn the material, another goal of the method, is to teach students life skills like respect for other people, planning, problem solving, taking chances in public, and communication skills. The teacher remains actively involved, stepping in to further explain or provide support if the teaching-students falter or the learning-students do not seem to understand the material. The method is distinct from tutoring in that LdL is done in class, supported by the teacher, and distinct