Twenty-four severely mentally retarded adolescents (with no uncorrected visual or hearing losses) were trained to use 16 manually signed English signs. Ss were randomly assiged to sign only, or sign plus speech conditions and performances were videotaped. Analysis of results revealed that all Ss learned some signs to criterion and all showed…

Investigated were aspects of language development (association, memory, comprehension, and production) in three groups (50 individuals per group) of deaf adolescents who were variously trained by the pure oral method, the combined oral-manual method, and the Rochester fingerspelling method. One hearing group was matched with the deaf in age, and…