Modélisation du concept d’image en optique géométrique par les apprenants de la classe de première scientifique à travers la démarche d’investigation comme mode de transposition didactique.

Abstract

Our study focuses on the modeling of the concept of image in geometric optics by première (1ère) science class learners. Several works in didactics of physical sciences present the difficulties posed by the concept of optical image in it teaching and learning process, these difficulties and observations made on the field , helped us to formulate the problem of the construction of the image of an object through a thin lens by learners of p première (1ère) science. Thus, in order to improve learner's understanding of the concept of optical image, a teaching method that takes into account the ability of learners to design and conduct a scientific process; to formulate scientific explanations using experimentation to prove their hypotheses, seems to be the appropriate teaching method. We therefore opted for the investigative approach to tackle this concept. This is how our main research hypothesis emerged, that is a teaching-learning sequence through the investigative approach improves the understanding of the construction of the image of an object through a thin lens in a première science class. We used different specificities of the investigative approach to put forward two secondary research hypotheses. In order to verify our hypotheses, we conducted a quasi-experimental research on the learners of the PC1 and PC2 classes of GBHS Mimboman using a reasoned choice sampling technique. Our total sample consisted of eighty-nine (89) learners: forty-four (44) constituted our experimental group (EG) who took the course on the characterization of the image of an object given by a thin lens by DI; forty-five (45) others formed the control group (CG), having followed the same course through the classical teaching approach. The results obtained in the various tests underwent a quantitative analysis. From the post-test, the results obtained allowed us to verify our research hypotheses, it appears that: for the first specific hypothesis, the average scores of the respondents according to response modalities for the CG goes from 47.9% in the pre-test to 54 , 44% at post-test; and in the EG it goes from 45.7% at the pre-test to 85% at the post-test, for the second specific research hypothesis, the average for the CG goes from 42.22%at the pre-test to 42.96 % at the post-test while in the EG, it goes from 52.05% at the pre-test to 70.57% at the post-test. From these results, we concluded that a teaching-learning sequence through the investigative approach improves the understanding of the construction of the image of an object through a thin lens in première (1ère) science.