The criteria of classification of inert matter in Primay Education: conceptions of students and competency levels

This article describes and analyzes the criteria elementary students used to classify inert matter and how they use the basic criteria of classification (pure substance/mixture). The study was conducted with 55 students of 2o, 4o and 6o of Primary Public School Trabenco Leganés (Madrid), from data supplied by an image classification task developed for this purpose. The results suggest that students use a variety of criteria based on the perception an use, and the criteria for natural/artificial and one /multiple components to apply the basic criteria classification of inert matter.Finally, as the main educational implication proposed different levels of competency in the classification of matter at Primary Education.