Transformative Teaching Strategy and Design to handle Pre-concepts in "Matter State Changes" in Junior High School Science

Concept is a systematic element in junior high school subject knowledge, and concept learning is not only concept acquisition, but also includes concept transformation. In order to effectively transform students' pre-concepts, this study takes the chapter of "matter state changes" in junior high school science as an example. On the basis of the previous inquiry and analysis of the pre-concepts, a targeted teaching strategy of the pre-concept transformation is proposed. Teaching strategies include exploring learners' pre-conceptions, setting up experimental situations, scientific reasoning, analogizing the pre-concepts and science concepts, and integrating students' knowledge. Meanwhile the relevant teaching design of the state of "white gas", endothermic and exothermic, factors affecting the speed of liquid evaporation, the substances inside the bubble and the condition of bubble motion when water boils, dry ice stage effects, etc., are presented. It is hoped that by making such attempts to effectively transform students' pre-concepts, help students establish science concepts. and realize the adjustment and change of the original cognitive structure.