G. Rodriguez-Morales, J. Ruiz-Mendoza, N. Alvarez-Aguilar

Universidad Autónoma de Nuevo León (MEXICO)
Traditionally optical theme is one of the most complex issues . While conducting this research surveys were conducted about the working nature of optical instruments such as microscopes and telescopes. Surveys were applied to students and teachers in secondary education in the third grade. Data corroborate the complexity of the topic because despite the physics themes has been studied in class, survey results reflect a low understanding or total ignorance of the optics working principles. Due to this problematic situation a didactic strategy was applied where in a sole activity the student can: observe, model, interact, interpret, describe and argue about the physical phenomenon. It was necessary to use software and equipment about geometrical optics designed for this purpose by the authors.

Concerning the optics software, it is designed for use in different modes: demonstration level of Geometric Optics, and problem solving classes, as a test in problem design or as a learning tasks that are designed as open problems, and as a result have a lot of different answers to enable the student argue and express conclusions. The geometric optics equipment of minimalist construction will allow students to understand the basics of Geometrical Optics. These two resources allow to consummate the link between theory and practice, and the teaching strategy proposal was designed based on that fact..

For the application of the didactic strategy, it was necessary to train teachers though a ten hours course, with twenty teachers of secondary education level. The activities in the training are: explanation of behavior of imaging of lenses, interaction with the geometrical optics experimental equipment, by ray trace, teachers, test the image formation by lenses and mirrors to achieve a better understanding of image formation. While experimenting, problematic questions were made to teachers, questions that call for reflection and opinion exchange between teachers about according the position of the object relative. After the experimental activity, the teacher were asked about the possibility to simulate the optical phenomena that rules the optical instruments. Using this resource teachers were lead to simulate the operation of the refractor telescope, the microscope and the photographic camera.

This way to study optical phenomena allowed its study in an integral form, that mean, in the same didactic activity is possible to reach three essential moments: observation, to understand how the phenomenon will be manifested, penetration in its regularities through the software modeling and verification by experimental activity. The dynamic nature of these different moments associated with the use of different didactic material and resources allow to work the observation and interpretation in the same activity, this process allow the teacher to gradually develop interpretative logic because they can explain with its own words the observed phenomena. Once finished the training experience, surveys were applied to determine the degree of comprehension of the optical phenomena. The survey shows that teachers present a tendency to skill development, an increment on its possibilities of critical reflection and auto-criticism. Teachers , reflect , valued and use the acquired knowledge, linking it with activities and practical situations of everyday life and in its context.