Less than a third of the studies that test ABA-related interventions are randomized controlled trials, according to Project AIM. And single-case designs make up the bulk of studies included in national reports issued to U.S. clinicians. For example, the 2021 National Clearinghouse on Autism Evidence and Practice (NCAEP) report deemed 28 practices evidence-based, including many behavioral interventions, yet 85 percent of the studies reviewed are a single-case design. So too, the 2015 National Standards Report (NSP) identified 14 effective interventions for autistic children, adolescents and young adults but draws on a set of studies of which 73 percent are single-case.
