This article presents the development and testing of a computer program for semi-automatic production of concept maps. This technique derived from information extraction intends to provide a simple and significant representation of the content of one or many texts by a knowledge diagram. The application was tested with two text corpora chosen for covering two themes coming from the Programme de formation de l’école québécoise of Secondary 4 in science and technology. The very encouraging results demonstrate the potential of this approach for easing the construction of concept maps, a process that is usually performed by humans. The results arouse as well some questions about the current methods for creating and assessing concept maps.