Non-Speech language systems serve primarily as a prosthesis for individuals who cannot or have not acquired language through the natural developmental process. To this end, non-speech research is currently in progress designed to determine the utility of finite and prefabricated response modes (plastic chips), and visible fine motor response modes (sign language) in the acquisition of language skills, and eventual transfer to a spoken response mode. Subjects are non-verbal severely and profoundly retarded children. Primary aims of the research include: 1) Determining what, if any, facilitative effect non-speech response modes such as Non-Slip-and sign language have upon the acquisition of speech; 2) Determining the most effective and efficient tactics for bringing about the transfer of linguistic rules from a non-speech to a spoken symbol system; and 3) Examining individual subject characteristics and subsequent program success to delimit criteria for entry into language training in various response symbol systems.