This investigation attempted to identify if AAC aided recasts enhance grammatical acquisition for emerging morphosyntactic structures, including past tense verbs, question words, and question syntax. In a telepractice setting, during shared book reading, LAMP Words for Life@ was used to enhance recasts for four elementary-schoolage children with severe language impairments. A nonconcurrent A-B design with varying baseline lengths demonstrated a correlation between AAC aided recasts for three out of four participants. Visual analysis revealed therapeutic changes for Participants 2, 3, and 4 as more than two consecutive data points fell above the two-standard deviation (2SD) band of the baseline, percent non-overlapping data (PND) ranged between 50% and 80%, and the slopes of intervention trend lines ranged between 3.04 and 19. Social validity suggested moderate positive outcomes with a small amount of effort required from parents. Strong interobserver agreement and procedural fidelity supported internal validity despite the use of a quasi-experimental design.
Keywords: severe developmental language disorder, language therapy, expressive language therapy, LAMP Words for Life, explicit language intervention, specific language impairment
