A professional development activity combining group sessions with self-study assignments was used to facilitate early intervention providers' use of participation-based practices. The activity was submitted by 96 providers who completed two videotapes of sessions with families and children. Tapes were coded to identify the type of service provided. Almost 60% of the providers demonstrated participation-based practice at the completion of the training, but 40% continued to provide services in the traditional way. Participation-based providers' beliefs were more closely related to recommended practices than beliefs of the traditional providers. Provider beliefs and perceptions aligned with their use of either participation-based or traditional practices suggesting that professional development designed to promote practice adoption should clearly articulate the beliefs underlying the practice and address participants' current beliefs and perceptions by providing opportunities for reflection and the alignment of personal beliefs and perceptions with those underlying the practice. (Contains 5 tables.)