Maintenance in Mathematics for Individuals with Intellectual Disability: A Systematic Review of Literature.

Despite the growing attention being paid to teaching mathematics for students with disabilities, the existing research tends to focus on mathematical skill acquisition, but not on skill maintenance. The researchers in this study reviewed all studies from 1975 to 2018 that involved teaching mathematics to individuals with intellectual disability. A total of 135 studies met inclusion criteria, but only 53 studies involved a maintenance phase (39.2%). Among the 53 studies, only 22 were included for the final analysis, after evaluating their methodological rigor. In those 22 studies, there was no consensus among researchers on the standards for conducting a maintenance phase (i.e., latency between intervention and maintenance phases, length of maintenance phase, number of maintenance sessions). Further, in the studies which included a maintenance phase, the most widely taught mathematical content was numbers and operations. All studies employed intervention packages which included more than one instructional method and/or materials and the most widely used instructional method was prompting while the most widely used instructional materials were visual supports and manipulatives. The results suggest that prompting is an evidence-based practice for individuals with intellectual disability in supporting maintenance, while explicit instruction, time delay, feedback, and instructional sequence (e.g., the virtual-representational-abstract instructional sequence) are potentially evidence-based practice for individuals with intellectual disability.