How to teach statistical concepts to slow-learning pupils

The so-called operative method has its roots in the work of J. Piaget. His concept of the "operation", both concrete and formal operation, and the psychological approach. We have learned from psychology that the learning of operational concepts has to be linked with the attributes of the operative method above mentioned. It is the experience of many teachers that pupils accept and make use o the operative attributes when problems are posed according to the operative principles, that pupils deal - sometimes - consciously with these attributes of tasks or problems, and that a special sort of active behavior is developed during a long term learning process according to this didactical design. Pupils between 12 and 15 years of age - especially the "slow-learners" - have to solve a large number of assignments before they can begin and carry out a process of generalization. One of the goals is to concretize learning through discovery; therefore formal solutions remain somewhat in the background, whereas more emphasis is placed upon the activities of the pupils and their dealing with variation in situation and tasks.