The study of developmental disabilities, not being confined to one medical field, poses a challenge in evaluating outcomes research. It is a multidisciplinary area of study which encompasses health-care, rehabilitation, psychosocial, educational, and biotechnology specialties and involves biological, social, and behavioral effects of intervention. Consequently, there is a lack of consistency in what has been studied, how the outcomes have been measured, and where these results have been recorded. Naturally, these disparate outcomes data need to be consolidated in such a way that comparison of treatments can be made, within and across professional disciplines.