Center for Autism Spectrum Disorders

The National Research Council addressed this issue in their report "Educating Children With Autism". They state:


“The committee recommends that children with any autistic spectrum disorder (autistic disorder, Asperger’s disorder, atypical autism, PDD-NOS, childhood disintegrative disorder), regardless of level of severity or function, be eligible for special education services within the category of autism.” p. 3.

National Research Council (2001) Educating Children with Autism. Committee on Educational Interventions for Children with Autism. Division of Behavioral and Social Sciences and Education. Washington, DC: National Academy Press.
http://www.nap.edu/catalog/10017.html

They go on to elaborate:


Although experienced clinicians and educators can reliably identify the constellation of behaviors that define autistic spectrum disorders even in very young children, distinctions among" classical" autism and atypical autism, PDD-NOS, and Asperger's Disorder are not nearly as reliable. Thus, though the identification of categories within the autism spectrum is necessary for some research purposes and is an important area for research, the educational and clinical benefit of making such distinctions is not yet clear.

Altogether, the most important considerations in devising educational programs for children with autistic spectrum disorders have to do with recognition of the autism spectrum as a whole, with the concomitant implications for social, communicative, and behavioral development and learning, and with the understanding of the strengths and weaknesses of the individual child across areas of development.