El trabajo práctico de laboratorio en la enseñanza de las ciencias naturales: una experiencia con docentes en formación inicial.

This article presents the research results of a training experience for future teachers of natural sciences. The objective of this research was to contribute to training process aimed at transforming the teachers' experimental practices for the teaching of specific topics of biology and chemistry, from the way the experimental practices are conceived, planned and implemented in school contexts. The proposed methodology followed the participatory action research approach and the case study method. The investigative process consisted of four phases to planning, implementing, evaluating and systematizing a model of experimental practice for the teaching of natural sciences. The sample was composed of five professors of natural sciences in the initial formation of basic education of the Universitdad del Valle. The main conclusions showed that the proposed model of experimental practice based on problem solving is more coherent with the contributions of current educational research and the nature of science, scientific activity, in which the relationship theory-experimentation is closely linked. The formative experience led to strengthen the knowledge base of the future teachers, which is reflected in the proposals planned and applied in school contexts; alternatives to the traditional practical works of demonstrative and illustrative type of theory. [ABSTRACT FROM AUTHOR]