Baseline PhaseDuring baseline, the researcher provided the children with time to communicate, used expec- tant delay (i.e., paused and looked expectantly at the child), and ensured access to the aided AAC system. After the child took a communicative turn and/or completed an action during play (e.g., pointing to the girl and then the bus), the instru- ctor waited a minimum of 1 s to ensure the child’s turn was complete and then provided a spoken model (e.g., The girl’s gonna hit the bus!). The spoken models reflected the child’s communica- tive behaviors, including what the child looked at, pointed to, played with, and/or said (Siegel & Cress, 2002). If a participant said or did nothing following the researcher’s presentation of a spoken model, the instructor provided an expec- tant delay (i.e., paused for the child’s typical turn transfer time 5 s and looked expectantly at the child) before providing another spoken model. Each spoken model consisted of a brief utterance that contained at least two of the vocabulary words included on the AAC system for that particular play scenario. The instructor provided a minimum of 30 spoken models within each session.