The long-term objective of this research program is to characterize and to facilitate the language development of young children with a variety of established disabilities who encounter significant difficult acquiring speech. Sixty children will be assessed, randomly assigned to participate in one of three interventions, and followed at 6- and 12-months after the intervention. The specific aims are: 1) to develop a fine-grained 18 month longitudinal description of the communication development of 24-36 month old children; 2) to compare the effects of three interventions: Augmented Communication Input (ACI) which focuses on comprehension, modeling, and augmented input, Augmentative Communication Output (ACO), which focuses on production and augmented output, or Non-Augmented Communication (NAC), which focuses on a well-established spoken communication intervention, on the comprehension and production of symbols and words, the transfer of skills to hormone, and parental perception of child communication; and 3) to determine the effects of the interventions on communication, adaptive behavior, and educational placement at 6- and 12- months following the intervention. During Pre-Intervention, the 60 participants will complete an assessment battery that includes descriptive, cognitive, communication, and family measures and provides a baseline database on each child. In Intervention, the children will be randomly assigned to one of the three interventions to determine the effects of two augmented language interventions versus oral communication intervention. In each intervention, the child and parent will participate in two 30-minute sessions a week across a 12 week period. Generalization to home, words/symbols comprehended and produced by the child, and parent perception of the child's communication will be assessed. In Follow-Up, 6- and 12-months post intervention measures of communication, adaptive behavior, parent perception, and educational placement will be administered. Findings will advance knowledge about the role of augmented language systems early in life and facilitate the children's adaptive behavior, educational placement, and long-term integration into society.