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. Maintenance of mathematical skills is especially important as mathematics has applications in daily life and is directly related to important life skills such as purchasing, calculating tips, and budgeting. In addition, maintenance of basic mathematical skills is necessary for advancing to higher grade-level contents because mathematical contents build upon previous contents. This dissertation is comprised of three stand-alone but inter-related studies that explored the maintenance of mathematical skills among students with disabilities. The researcher conducted a systematic review of the literature regarding attention to maintenance when exploring mathematical interventions for students with intellectual disability and autism. The researcher then conducted two original studies, each which examined the effectiveness of an intervention package---the virtual-representational-abstract (VRA) instructional sequence with fading support and the VRA with overlearning---to promote maintenance of basic operations skills among students with disabilities. In the first study, to determine the extent to which researchers focused on skill maintenance in teaching mathematics, the researcher reviewed all studies from 1975 to 2018 that involved teaching mathematics to individuals with developmental disabilities. A total of 128 studies met inclusion criteria but only 46 studies involved a maintenance phase (35.9%). Of the studies that included a maintenance phase, there was no consensus among researchers on the standards for conducting 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. The second study was an experimental research study which used a multiple probe across participants design to examine the effectiveness of the VRA instructional sequence with fading support in teaching subtraction with regrouping to four students with disabilities, including intellectual disability and/or autism. A functional relation was found between the VRA instructional sequence with fading support and students' accuracy in solving the problems. Students also maintained the skill up to six weeks after the intervention. The third study also utilized a multiple probe across participants design to evaluate the effectiveness of the VRA instructional sequence with overlearning in teaching multiplication to three students with disabilities. A functional relation existed between the VRA instructional sequence with overlearning and accuracy of solving multiplication problems. Students also maintained the skill up to eight weeks after the intervention. Overall, in this dissertation, intervention packages including more than one instructional, or a combination of instructional methods and materials were not only effective for skill acquisition, but also for skill maintenance. The review of literature identified explicit instruction with visual supports, manipulatives, or task analysis as potentially beneficial packages for promoting maintenance while the experimental studies demonstrated the effectiveness of the VRA instructional sequence with fading support or overlearning.
Read
