The PISA 2000 study found large differences between countries in terms of quality of learning. In some countries, students prefer rote learning to meaningful learning. However, such memorisation of the material does not lead to recallable and usable knowledge in the long run. Ausubel's (1968) well-known theory serves as a basis for several techniques of meaningful learning, including concept mapping, which emphasises the visual organization of comprehended information. The present study reports the results of an experiment using concept mapping for deepening students' understanding of teaching materials. It focuses on definitions frequently used in science and Hungarian grammar lessons. Results indicate that concept mapping training programmes can improve participants' achievement. Experiences show that the technique of concept mapping is frequently unfamiliar to students. More time would be needed for practising and using it in different learning situations.