Effects of the science writing heuristic approach with using multimodal representations on students' academic achievment and criticall thinking in science education

In this study, it was aimed to investigate the effect of Science Writing Heuristic approach (SWH) with the use of multimodal representation (MMR) on academic achievement and critical thinking skills of 6th grade students in science education. Quasi-experimental design, one of the quantitative research methods, was used in the study. In this context four groups were included in the study, one of them was control group and others were experimental groups. The groups were randomly assigned as control or experimental. The control group didn't have any experimental intervention and it's carried out with teaching methods and techniques in the lesson plan. Experiment A group teaching method was SWH approach and they were used multi modal representations, Experiment B group teaching method was only SWH approach, Experiment C group were used multi modal representations in two different units. Academic Achievement Test and Critical Thinking Test were used as data collection tool for both units at the beginning and the end of implementations. In addition, the experimental reports of students in the groups that were taught with SWH approach and poster assignments in the groups that were used MMR were also analyzed. A pilot study was carried out to reveal the problems that may be encountered and to determine the applicability of the study. Problems encountered in pilot study were analyzed, changes were made in line with expert opinions/suggestions and then study was implemented. U1 and U2 academic achievement tests and EDT performed at the beginning of the application, these tests results analysis showed that there was no significant difference between the groups except for the total scores of U1 multiple choice questions. When the post tests were analyzed, it was determined that the Experiment A group differed significantly and was more successful than other groups in U1 unit. While there was no significant differentiation between the Experiment B and Experiment C groups in the U1 unit, it was determined that both the Experiment B and Experiment C groups differed significantly compared to the control group. It was determined that the Experiment A group still differed significantly and was more successful than the control group and Experiment C group in the U2 unit. In terms of critical thinking skills, it was determined that there was a statistical significant difference in favor of the Experiment A and Experiment B groups in the EDT posttest compared to the control group. EDT posttest score show that there was a significant difference between Experiment B and Experiment C in favor of Experiment B group. The groups where the use of SWH approach and MMR are carried out separately yields effective results in academic success compared to the control group; when the SWH approach and the MMR are implemented together, it is seen that they produce more effective results in academic success. However, it is another result of the study that SWH approach affects critical thinking skills positively, and students' use of MMR may not affect their critical thinking skills. Key Words: Science education, argumentation, science writing heuristic, multimodal representations, academic science achievement, critical thinking