The effectiveness of different instructional intervention on critical thinking skills in middle school: A meta-analysis study

In this meta-analysis study, it was aimed to determine the common effect size of experimental studies on middle school students' critical thinking skills with different classroom practices in science education and to examine them in terms of moderator variables. Using the Prisma flow chart, 57 studies published in Turkish, English and Spanish between 2000 and 2022 in master's and doctoral theses and refereed journals were included in the study. In order to conduct meta-analysis, these studies were read in detail and repeatedly, coded and descriptive statistics were performed. The results of the descriptive statistical analysis showed that most of the studies were conducted with argumentation and STEM applications, in the subject area of physical phenomena, to improve the critical thinking skills of 7th grade students. It was also found that most of the studies were conducted in Turkey and Asian countries. It has been observed that the number of studies on critical thinking has increased significantly after 2000 in the world and with the science curriculum changed in 2018 in Turkey. In other words, it was observed that the changing science curriculum guided the research topic selection of science educators especially in Turkey. The effect size obtained from the meta-analysis showed that the critical thinking skills of middle school students did not differ between grade levels and could be developed at every grade level with different classroom practices. However, it was revealed that it was more effective when the topic "Living Things and Life" was preferred and done with 5E classroom practice. In addition, it was determined that data collection tools developed in different countries other than standardized tests such as California and Cornell gave higher results for the change in critical thinking skills. It is thought that the low reliability and validity of these tests are effective in this. In the studies with true/quasi-experimental design, it was concluded that only the duration of implementation between "1-4" weeks was more effective in the development of critical thinking skills than the studies with "5 weeks or more". Finally, the results of the meta-analysis showed that the science curriculum in Turkey, which has changed four times in the last 22 years, is insufficient in developing critical thinking skills of middle school students. It is thought that teacher performance, teaching materials and classroom practices are the reasons for the inadequacy of the curriculum.