A microworld to implant a germ of probability

This paper reports on the third part of a long term experiment concerning the introduction of 12-13 years old pupils to the concept of randomness and probability. In the first parts, the pupils analysed the concept of randomness, in daily life and with LEGO-RCX robots. The third part is based on the Random Garden Game (within the programming environment ToonTalk). The pupils are guided towards the concepts of equivalence of sample spaces and of classical probability, through temporary and personal meanings, corresponding to an evolution by means of class discussions.