Acquisition of the commenting function among system users

The present study explored context, partner, and subject variables in the acquisition of the commenting function by three AAC system users in a special day class program. A multiple baseline study across subjects was designed to measure (1) individual subject's acquisition of 10 different comments when provided with a “least-to-most” intrusive prompting hierarchy; (2) spill-over effects when one subject was receiving treatment with the other subjects present; and (3) context generalization. All three subjects acquired the commenting function. However, there were differences between subjects in the types of prompts they responded to, the extent of spill-over effects, and context generalization. The results are discussed with respect to the effectiveness of the treatment employed across subjects and implications for teaching communicative functions.