Modelos mentales de estudiantes de educación secundaria sobre la transformación de la leche en yogur

Abstract

The students’ mental models provide valuable information about their conceptual frameworks, that is, their underlying structures of knowledge that can help improve the design of the learning activities in class. This paper investigates the mental models of 153 secondary students aged 13 to 15, on the milk transformation into yogurt and a teaching model is proposed. The data were collected with two tasks that demanded to explain this transformation through verbal answers and drawings. Based on the students’ responses, seven different mental models were identified, of which four (the fermentation is a mechanical process, implies an increase in the number of bacteria, it consists of a mixture, and the bacteria as a binder of molecules) must be regarded as a contribution of this work to not have been identified in previous studies in this educational stage. However, the models are still very far from the lactic fermentation school model, and new didactic strategies should be tried to move forward in their progression.