Özet:

This research aims to study the impact of the teaching materials developed for the REACT strategy within the framework of the structure and characteristics of the material on the student's conceptual understanding. The research is carried out with the preliminary test - final test control group design of the experimental research method. The experimental group 50, the control group 51 and 101 of the 6th class students participated in the research. The teaching material is developed in the framework of the main context of the hot air balloon and the work principle. The research data was collected by a conceptual test consisting of two stages of questions. The data obtained from the concept test was submitted to the Mann Whitney-U test. The findings show that the teaching material performed in the experimental group is more effective than the teaching material performed in the control group. The findings obtained from the research indicate that students have created alternative concepts by putting the observable properties of the substance on the substance, by gradually generalizing the physical-chemical changes, by influencing what they learn about intensity in daily life. Although the teaching materials developed on the basis of the REACT strategy have influenced the conceptual change, it has been determined that there are alternative concepts that cannot be changed by scientific knowledge. The teaching can be enriched by adding different conceptual change pedagogies to the existing teaching materials for these alternative concepts.