Evolution of Conceptions in a Mathematical Modeling Educational Context

We deepen the problem of conception evolution, focusing our attention on the con¬ceptions that more frequently come out in a long term experimentation on the sun shadow phenomenon. This analysis points out that naive conceptions, expressed by the pupils before a systematic study of the phenomenon is performed, usually evolve due to the classroom activity, even when they are not explicitly object of didactic in¬tervention, either interlacing with new conceptions, or being substituted by them. Using one or another conception seems to depend on various factors of cognitive re¬levance. The result is a not linear personal path, where naive conceptions can come out again even after more scientific ones have been learned and successfully applied.