Effects of a phonics-based intervention on the reading skills of students with intellectual disability

Background: To date, only a few studies with randomized controlled trials have been published on the effectiveness of phonics-based reading interventions to teach decoding and spelling skills to students with intellectual disability. Aims: This study evaluated the effects of a phonics-based reading intervention program on the progress of French-speaking elementary students with intellectual disability. Methods: A total of 48 non decoding elementary students with intellectual disability were randomly assigned to either a treatment group or a control group. Most of the participants (75 %) had nonverbal IQs below 55. The reading intervention program was implemented for seven months by the students' teachers and mainly in a small-group format (two to four students). Results: Students from the treatment group made significantly more progress in word and nonword reading measured by a researcher-designed test with a medium effect size. An almost significant difference was also found on spelling (p = .058) and on word and nonword reading measured with a standardized test (p = .060) with medium effect sizes. Conclusions: These findings suggest that students with ID benefit from phonics-based programs integrating research-based approaches and techniques.