Using aided AAC models, recasts, and contrastive targets to teach grammatical morphemes to children who use AAC

The purpose of the investigation was to evaluate the effects of using aided augmentative and alternative communication (AAC) modeling and recasting on the expression of grammatical morphemes with children who used AAC.

A single-subject, multiple-probe, across-targets design was used for the study. Three participants were each taught to use 3 grammatical structures. Intervention consisted of aided AAC models and recasts during storybook reading tasks.

All three children readily began using the targeted grammatical morphemes. However, none of the participants maintained use of the first morpheme. Error analyses revealed that the children either omitted the targeted morpheme or replaced it with another morpheme. To address this issue, a second intervention phase was implemented for the targets that were not maintained. During this phase, various grammatical morphemes were contrasted with each other (e.g., past tense -ed vs. possessive 's). Following the second intervention phase, participants maintained all targets.

Aided AAC models and recasts may be used as part of intervention packages designed to help children acquire production of grammatical morphemes; however, it is important to provide contrasts of grammatical forms to ensure acquisition. Theoretical and clinical implications are discussed.