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.