issues: application of standardized procedures for describing participants in intervention studies, including children’s diagnoses, chronological age, developmental and behavioral information, family information, gender, sociometric status, race, and pertinent health or biological information; the association between fidelity of treatment information and treatment outcomes; the association between participants’ characteristics and treatment outcomes (e.g., aptitude-by-treatment interactions); the development of early identification procedures and their relationship to early access to services; and identification of program features (i.e., “active ingredients” of intervention programs) that relate most directly to child and family outcomes. The impact on growth for young children with autistic spectrum disorders may be measured by techniques such as growth curve analysis, hierarchical linear modeling, and/or structural equation modeling to model the longitudinal growth and treatment.

Addressing these methodological issues will require larger sample sizes, longitudinal follow-ups of participants, and interdisciplinary collaboration. To enable such needed research, initiatives should be funded jointly by federal agencies responsible for research, development, and services for young children with autistic spectrum disorders (including the Office of Special Education Programs, the Office of Educational Research and Improvement, the National Institute of Child Health and Human Development, the National Institute of Mental Health, the National Institute of Neurological Disorders and Stroke, and the National Institute on Deafness and Other Communication Disorders). These initiatives should include a task force that meets regularly to design and provide a synthesis of the diagnostic, developmental, behavioral, and treatment research that would inform the design and implementation of early educational treatment for young children with autistic spectrum disorders; consideration of the feasibility of a national, cross-site, longitudinal investigation of early intervention treatments for young children with autistic spectrum disorders and their families; and development of specific measurement tools for early diagnosis of children with autistic spectrum disorders and treatment outcomes (e.g., social functioning, spontaneous communication and language, peer relationships, and competence in natural settings). Agencies funding competitive research initiatives should include personnel with sufficient research and experiential background to judge the scientific and practical merits of proposals.