Effects of Inclusive-Geoboard and Braille Mathematical Codes on Geometry Achievement among Students with Visual Impairment in Nigeria

This study examined the effects of inclusive-geoboard instruction and Braille mathematical codes on geometry achievement among students with visual impairment in South-West Nigeria. A quasi-experimental pretest-posttest non-equivalent control group design was adopted. Using a multistage sampling technique, 135 students were selected from designated mainstream junior secondary schools, comprising 90 students in the experimental group and 45 in the control group. The intervention lasted 12 weeks. Data were collected using the Geometry Achievement Test, Braille Mathematics Competence Scale, Geoboard Instructional Guide, and Classroom Observation Schedule. The instruments were validated, and reliability coefficients were obtained for the Geometry Achievement Test (alpha = 0.82) and Braille Mathematics Competence Scale (alpha = 0.77). Data were analysed using descriptive statistics and Analysis of Covariance at the 0.05 level of significance. The results showed a significant effect of inclusive-geoboard instruction, F(1, 131) = 31.42, p < .001, and Braille mathematical codes, F(1, 132) = 38.37, p < .001, on geometry achievement. A significant interaction effect was also found, F(1, 130) = 18.14, p < .001, with the model explaining 37.9% of the variance in achievement (R² = 0.379). The findings indicate that tactile manipulation and Braille notation can support access to geometric concepts among students with visual impairment. The study recommends the provision of tactile instructional resources and improved teacher training in Braille mathematics.