Pediatricians serve a vital role in identifying young children with developmental delays and disabilities and referring families for services to support their children's development and learning. However, past researchers indicated there is minimal research on training pediatricians on the Part C early intervention (EI) process that supports young children with developmental delays and disabilities. This study examined the effectiveness of a web-based training on pediatricians' knowledge of EI services and referral processes. The training components included interactive, online modules and paper resources directed towards an understanding of EI services. A convergent parallel mixed-methods study design was used to determine the outcomes of pediatricians' use of the web-based training module and participants' preferred training methods. Results showed that an interactive online training for pediatricians was associated with significantly increased knowledge of EI services. It was found that the majority of participants preferred the online training method and were satisfied with the training content. Thus, the study provided the information necessary to guide future research on implementing training programs for pediatricians. Finally, these knowledge gains should lead to increases in referrals of young children that would benefit from EI services. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]