Habtamu Wodaj (PhD)Wuleta Ketema2024-11-202024-11-202024-05https://etd.aau.edu.et/handle/123456789/3642The main purpose of this study was to investigate the effect of a context-based Relating, Experiencing, Applying, Cooperating, and Transferring (REACT) instructional strategy on students’ scientific reasoning skills, conceptual understanding, and epistemological beliefs on heredity concepts. In this study, a mixed-methods approach and a convergent embedded experimental design were used. One hundred thirty-one tenth grade students took part in the study. Both quantitative and qualitative data were collected. Three schools and three intact classes were selected randomly from each school. Treatment groups 1, 2, and comparison groups were assigned randomly to each school. Treatment group 1 received a context-based REACT instructional strategy; treatment group 2 received conventional instruction integrated with context-based activities; and conventional instruction was used alone to teach heredity concepts in the comparison group for six weeks. All groups received pre- and post-tests of the genetics conceptual understanding test, scientific reasoning skill test, and epistemological beliefs questionnaire. During the intervention, classroom observations and, after the intervention, semi-structured interviews were conducted. The quantitative data were analyzed using multivariate analysis of variance (MANOVA) and analysis of variance (ANOVA), while narrative analysis was used to analyze the qualitative data. The MANOVA results showed that there were significant mean score differences between treatment group 2 and the other two groups in favor of treatment group 2 in both conceptual understanding and scientific reasoning skills. Nevertheless, there was no significant difference between treatment group 1 and the comparison group in both variables. The observation and interview results supported these findings. The one-way ANOVA result also showed that there were significant mean score differences between the groups in favor of the treatment groups when it came to epistemological beliefs. However, there was no significant difference between treatment groups 1 and 2. This suggests that, compared to conventional instruction, the context-based instructional strategy had a positive effect on students' epistemological belief shifts toward expertise. In conclusion, this study found that integrating context-based activities with conventional instruction has more effect on three variables than context-based REACT strategy and conventional instruction alone. Key words: context-based instruction, conceptual understanding, scientific reasoning, epistemological beliefs, heredityencontext-based instructionconceptual understandingscientific reasoningepistemological beliefsheredityThesis