The purpose of this study is to investigate the effect of one year of regular "LEGO" training on pupils' performances in schools. The underlying pedagogical perspective is the constructivist theory, where the main idea is that knowledge is constructed in the mind of the pupil by active learning. The investigation has been made in two steps. The first step was before the training and the second after training. For both cases we have constructed and included control groups. A logistic model is applied to the data under consideration to investigate whether the LEGO training leads to improving pupil's performance in the schools. To analyse the opinion studies, GLM for matched pair models and the Quasi symmetry methods have been used. Preliminary results show better performances in mathematics for the trained group in grade five, and pupils who are good at mathematics tend to be more engaged and seem to be more successful when working with LEGO. The study has also shown that pupils have different learning styles in their approach to LEGO training. The role of the teacher, as a mediator of knowledge and skills, was crucial for coping with problems related to this kind of technology. The teacher must be able to support the pupils and to make them understand the LEGO Dacta material on a deeper level. (Contains 3 tables.)