This volume is about interprofessional communication and through an ethnographic, interactive sociolinguistic, and cultural approach introduces a discourse perspective to the analysis of interprofessional communication. It looks at the various participants - voices - present and absent, invited and uninvited - and their contributions to team discourse about children who are evaluated for mental retardation/developmental disabilities. The authors are particularly concerned about the parents' perspective and how their concerns about their children are perceived by professionals; and how professionals of various disciplines perceive each other and children. The authors view assessments as interactively constructed by the team and identify whose contributions enter into the discourse. Ultimately, they are concerned with whose voice counts and the impact of the interactive process on families and children.