Abstract
This article aims to show the impact of a practical course on saponification on the distinction between levels of knowledge. The study was carried out in Cameroon in a scientific 12th grade class. The class divided into two groups : "experimental" group having followed the practical training and "theoretical" group not having followed the practical training. An analysis was carried out in order to show that the students having followed the practical training circulate more between the levels of knowledge compared to those of the theoretical class.