Using a naturalistic time delay procedure to teach nonverbal adolescents with moderate-to-severe mental disabilities to initiate manual signs

This investigation focused on teaching 3 nonverbal adolescents with moderate-to-severe mental disabilities to initiate manual signs for the purpose of communication with others. The teacher introduced a naturalistic time delay procedure in a multiple baseline design, counterbalanced across students. She taught 3 signs to each student over 3 separate sessions throughout the day. Data show that the students increased signing over baseline condition in a variety of settings and throughout the day.