Provision of a language index for severely and profoundly retarded individuals.

The development of habilitative language programming for severely and profoundly retarded individuals requires detailed knowledge of their current levels of competence. Specific information is needed regarding the particular language skills characteristically displayed, the frequency with which such skills are used, and the proportion of severely retarded individuals who evidence linguistic abilities at the various levels. An index of language proficiency has been developed utilizing a standardized system of direct observation of subjects in their usual, familiar environment. Data on a group of ambulant, institutionalized, severely and profoundly retarded individuals were described. Some type of vocal or gestural communication was observed for about 75 percent of the subjects; almost 60 percent evidenced some vocal or verbal expression. One in four subjects demonstrated meaningful, articulate speech. Associations between language and factors such as sex, chronological and mental age, diagnosis, and biosocial history were investigated. Implications of these findings were discussed in relation to programs for language development.