Effectiveness of virtual-representational-abstract teaching strategy in teaching subtraction skills to students with autism spectrum disorder

The purpose of this study is to determine the effectiveness of the VRA strategy in teaching subtraction skills to students with autism spectrum disorder (ASD). The study examined the generalization effects of instruction delivered through the VRA strategy across different settings and individuals, the maintenance effect measured two weeks after the completion of instruction, and the social validity of the strategy based on the opinions of students and teachers. The dependent variable of the study was the students' performance levels in subtraction skills, and the independent variable was instruction delivered using the VRA strategy. A multiple baseline design across subjects, one of the single-subject research methods, was employed, and the participants consisted of three students aged 8–9 years who had been diagnosed with autism spectrum disorder. Individual instructional sessions were conducted at different times for each participant according to the steps of the selected direct instruction method. Data were collected using forms developed by the researcher during these sessions, and all sessions were recorded using a video camera. Social validity data were collected separately from both teachers and students. The results of the study indicated that instruction using the VRA strategy was effective, that the acquired subtraction skills were maintained over time, and that these skills were successfully generalized across different settings and individuals.