Children with autism spectrum disorder (ASD) and moderate to severe intellectual disability (ID) face many challenges. There is little evidence-based research into educational settings for children with ID and ASD and in France. Little is known about how this unserved population could benefit from intervention and education. | Developmental and sequenced one-to-one educational intervention DS1-EI for autism spectrum disorder and intellectual disability A two-year interim report of a randomized single-blind multicenter controlled trial