The effectiveness of the virtual-representational-abstract strategy on basic calculation skills on children with intellectual disability

The purpose of this study was to determine effectiveness of teaching basic calculation skills (addition, subtraction, multiplication and division) using the virtual-representational-abstract strategy on children with intellectual disability. This study also examined generalization effects accross different people and conditions, maintenance effect after 1, 2 and 3 weeks and social validity about teachers' views with this strategy. A single case multiple probe across participants design was used in this study. The dependents variable of this study were students' correct response with the skills of basic calculation skills whereas the independent variable of this research was virtual-representational-abstract strategy. In the research, a web-based virtual manipulative was developed to be used in the first phase of this strategy. Picture cards were used in the second phase and worksheets in the last phase. This study was conducted in the province of Bolu. Seven students with intellectual disability participated in this study. Students'age ranges from 7-12 years old. To analyze the data, researcher conducted visual analysis and elected to use effect size calculations. At the end of the study, findings of the study indicated that virtual-representational-abstract strategy was effective in teaching basic calculation skills to students with intellectual disability. These findings are supported by effect size calculations. Subjects were determined to retain their skills 1, 2 and 3 weeks after training sessions were terminated, and they were also noted to generalize the target skills across different settings and people. In addition, interviews with teachers reveal that their ideas are generally positive on the use of virtual-representational-abstract strategy instruction for students' calculation skills.