Student's Explanations of Chemical Phenomena: Macro and micro differences

This study investigated patterns of students' science thinking across four different science phenomena, focusing on changes with age and science education. British secondary school students in three age groups were offered sentences appearing on a computer screen that gave different explanations for four common changes in materials: ice melting, sugar dissolving in water, a candle burning and an iron nail rusting. The students were asked whether the sentences 'made sense' to them. The sentences, composed of fixed terms, were designed to embody good science explanations, common misconceptions, and basic descriptive and causal categories relating to the physical world. They were generated from a systemic network of explanation types. The results enabled new distinctions to be made between students' ideas at the substance, molecular and atomic level according to their length of time in science education. Implications regarding the age at which students are introduced to atomic theory are considered.