An Investigation of the Effectiveness of an Orton-Gillingham Based Reading Intervention in Kindergarten and First Grade Using a Fuzzy Regression Discontinuity Design
Delays in the development of early literacy skills are associated with a wrath of negative educational outcomes and so addressing such delays is one of the most pressing challenges in education. This study examines the effectiveness of the Orton-Gillingham (OG) Method, a multisensory reading program where instruction utilizes two or more senses simultaneously. Originally developed in the 1930s as a program for dyslexic students, OG has seen continual use since its creation and is endorsed by the American Dyslexic Foundation and the International Dyslexic Foundation. Over the past two decades OG has increasingly been incorporated into general education settings in the primary grades as a reading intervention for struggling readers regardless of whether they have dyslexia. However, there is a dearth of research demonstrating its causal effect as a reading intervention for children with dyslexia or who are experiencing reading delays for other reasons. Two quasi-experimental methods, Regression Discontinuity Design and Nonequivalent Comparison Group Design with propensity scores, are used to test the efficacy of an OG-based, general education reading intervention on a sample of over 700 kindergarten and first grade students who are experiencing reading delays from a large district in California. The Dynamic Indicators of Basic Early Literacy Skills (DIBELS) assessments were used to assign students to the intervention and measure their end-of-year reading outcomes. The results of both analyses revealed no effect for students enrolled in the intervention in either kindergarten or first grade. Within the year that students received the intervention, a small but non-significant gain on end-of-year DIBELS composite scores was found. Long-term outcomes showed that over half of the students in the intervention were still not meeting reading targets by the end of second grade. Moreover, while the treatment effect was found to vary significantly across classrooms and across schools, no available measures classroom or school characteristics where associated with that variation. These findings suggest that certain applications of the OG methodologies may not be effective in general education settings.