Communication forms and functions of children and adults with severe mental retardation in community and institutional settings.

The forms and functions of expressive communication produced by 84 individuals with severe mental retardation were assessed, using a structured communication sampling procedure. Symbolic communication acts were produced by 39 participants, and 27 of these symbolic communicators produced one or more multiword/multisymbol utterances. Of the remaining participants, 38 produced intentional but nonsymbolic communication acts; 7 were not observed to produce any intentional communication. For all participants who produced intentional communication, there were significantly more imperative than declarative communication acts. Significant differences in the frequencies and functions of communication acts produced by these participants were associated with differences in their communication levels (contact gesture, distal gesture, or symbolic), age (child vs. adult), and residential status (community home vs. large facility).