Students with mathematics learning disabilities have a weak understanding of mathematical concepts that underlie success in algebra I, such as ratios and proportional reasoning. In this study, researchers used a multiple-baseline across participants design to evaluate the effects of a intervention based on an instructional trajectory of how students come to understand ratios through build-up, emergent unit, and unit strategies on performance on a test of ratio equivalence. Student performance during intervention indicated a functional relationship between the instruction and higher scores on a curriculum-based measure across three students. Student use of increasingly sophisticated strategies over the course of the intervention also increased. Results as well as possible implications and future research are discussed.
Hunt, J. H., & Vasquez III, E. (2014). Effects of ratio strategies intervention on knowledge of ratio equivalence for students with learning disability. The Journal of Special Education, 48(3), 180–190. doi:10.1177/0022466912474102