Abstract:

Currently is well established that pre-conceptions or naïve theories (misconceptions) in science interfere in the process of students learning. These misconceptions will interfere their learning and difficult the connections with their existing knowledge. In general, misconceptions occur when the students’ beliefs or opinions are different from the concepts scientifically correct. Associated with the basic concepts that explain optical phenomena, such as the explanation of the light propagation, color, laws of reflection and refraction, there are several wrong ideas that prevail throughout the academic path of many students. On the other hand, the aforementioned concepts are part of the scientific basic knowledge of the primary education teachers. Therefore, to overcome existing misconceptions, some kind of conceptual change has to occur in the students’ minds. Then, is especially important to find teaching strategies to change student’s understanding of a concept when they experience misconceptions, that is, for students to change the concept they have toward the correct scientific concept and consequently that promote effective learnings.

This study focuses on learning of basic concepts of optics and was performed with students of the first year of the bachelor's degree in primary education with the aims; of identify misconceptions about the property of light reflection by ordinary objects and about the image formation by a plane mirror, before and after the teaching of basic concepts of optical phenomena of the program of the Physical-Chemistry Curricular Unit.

Data collection was done through a pre-test/post-test design. The students preformed the pre-test before being taught any optical topic. The pre-test consists of a set of questions about the light properties, and a month and a half later the students preformed the normal assessment test of the Physical-Chemistry Curricular Unit, which includes two questions that constitute the post-test; one about the laws of reflections and another about the image formed by a plane mirror. The two questions were part of the pre-test.

The metrics used in the quantitative analysis of the student learning were the normalized gain ⟨g⟩ and effect size Cohen's d. The student’s answers to each of the questions were analysed with both metrics. The results obtained with the two metrics were compared and a critical analysis has been made. Furthermore, are also presented a qualitative analysis of student´s misconceptions taking into consideration the methodology used to teach the properties of the light propagation and the formation of images.

Keywords:

Misconceptions, optics education, image formation, reflection laws.