Dispositif d’expérimentation portant sur la saponification et impact sur la distinction des niveaux empirique, macroscopique, microscopique et symbolique/visualisation de la chimie

Abstract

The levels of knowledge represent knots of unavoidable obstacles in learning chemistry in Cameroon as elsewhere in the world. However, it turns out that many students and teachers have difficulty distinguishing them. We want to see if the implementation of practical work on saponification allows students to distinguish between levels of knowledge. We have, firstly determined the origins of the difficulties related to the levels of knowledge, secondly, build a didactic engineering likely to help the pupils as well as the teachers to distinguish the levels of knowledge, thirdly, evaluated the influence of engineering on the distinction of knowledge levels. To achieve this, we explored several tracks such as the institutional track (analysis of chemistry programs from the 6th grade to the science 12 grade classes) in order to see the place occupied by the levels of knowledge in the program, the epistemological and conceptual tracks (analysis of the evolution of levels of knowledge), the historical tracks (analysis of learning difficulties relating to levels of knowledge). We have also set up a pre-test for students, a questionnaire for teachers in order to know respectively the apprehensions of students and teachers on the levels of knowledge. The analysis of the various results allowed us to set up a didactic engineering based on a circulation between the levels of knowledge in half of the three classes and, a post test in all the classes. The comparison of the a priori and a posteriori analyzes relating to the various tests (pre-test and post-test) carried out on 106 pupils of the 12th grade class (C and D) allows us to note that the pupils who took part in the engineering put in place better distinguish between the levels compared to those who did not take part. In response to the difficulties encountered by the students, a remedial activity was designed to help them better distinguish between the different levels of knowledge. At the end of our study, we came to the following conclusion: the experimental device on saponification helps students better understand the different levels of knowledge of chemistry. We suggest that designers of chemistry programs specify knowledge in terms of level in the chemistry program for better consideration in learning.