Implementation of the 8th grade "Pressure" unit in science education with the RADEC teaching model and semi-experimental research method.

The aim of the study is to determine the effectiveness of the RADEC learning model activities developed for the pressure unit of 8th grade middle school students in science course on students' academic achievement, research and inquiry attitude skills, and critical thinking skills. In the study, a quasi-experimental design, which is one of the quantitative research methods and consists of a pretest-posttest experimental and control group, was used. The study group of the research consists of 8th grade students studying in a secondary school in Amasya between 2024-2025 academic years. The study group of the research consisted of 34 students in total, including the experimental group (N=19) and the control group (N=15). In the study, RADEC learning model activities were applied to the experimental group, while the Science curriculum in effect in 2024 was applied to the control group. The data collection tools used in the study consisted of "Achievement Test Related to Pressure Unit", "Secondary School Students' Attitude Scale Towards Research Inquiry", "Readiness Scale for RADEC Learning Model", "Secondary School Students' Attitude Scale Towards Research Inquiry". Independent sample test was used to analyze the quantitative data obtained and ANCOVA analysis was used for the critical thinking power scale. Based on the findings, it was determined that there was no significant difference between the test scores of the experimental and control group students obtained from the scales for academic achievement, research inquiry and RADEC learning model before the application. It was determined that there was a significant difference between the critical thinking power scale test scores of the experimental and control groups. After the application, it was determined that there was a significant difference in favor of the experimental group in the test scores obtained from the academic achievement, research inquiry, RADEC learning model and critical thinking power scales of the experimental and control group students. It was determined that there was no significant change in research inquiry skills. As a result of the findings of the study, it can be concluded that the RADEC learning model improves the quality of learning. Since the RADEC learning model is important for students to gain competence in many areas and since such aresearch has not been studied in the Turkish context before, it is recommended for educators to use it, especially since it will contribute to the literature in the field of education