Demonstrations and problem‐solving exercises in school science: Their transformation within the Mexican elementary school classroom

In this article I argue that scientific knowledge in schools is a social construct in which curriculum proposals are just a point of departure that are transformed by the social interaction which takes place within the classroom. The participants of the educational process, teachers and students, reconstruct and elaborate new meanings for the proposed knowledge through a negotiation mediated by discourse. Thus, I consider that discourse plays an important role in scientific knowledge construction within classroom interaction. Empirical data of different science classes on topics such as chlorophyll, machines, solar system dynamics, and flotation phenomenon are shown. These themes are basic subject matters in the Mexican elementary school curriculum. These data are presented as ethnographic entries and are used as the basis for qualitative analysis. In this analysis we find that, when presenting experiments and exercises in science classes, teachers often make didactic transpositions which transform exercises that the textbook proposes as problem‐solving into demonstrations and, in other cases, transform demonstrations into problem‐solving exercises. Another more interesting result of this analysis is the emergence of a new transformation in the character of experimental activities which takes place as a result of students' interventions. In the interactive dynamics within the classroom, and especially with students' questions and interventions, the experimental activities suffer significant changes in relation to their orientation and to the constructed knowledge meaning. For example, we can find that the exercises set up by teachers as demonstrations are frequently transformed into problems as a result of children's interventions. These results show students as active participants in the construction of scholastic knowledge. They contribute with their own ideas instead of acting as passive receptacles of knowledge. Social interaction enhances scientific knowledge and transforms it into a social construction process that is alive instead of appearing as a set of ankylosing truths transmitted to students from textbooks and by the teacher. This kind of ethnographic research helps to set up bridges between didactic proposals and classroom work by contributing the necessary information to learn about the characteristics of knowledge constructed in the classroom and the conditions that influence the construction of this knowledge and students' scientific formation. © 1997 John Wiley & Sons, Inc.