Augmentative and Alternative Communication Generative Language Intervention: A Randomized Controlled Trial

Children with a wide range of impairments such as cerebral palsy and childhood apraxia of speech can benefit from augmentative and alternative communication (AAC). When AAC is provided, it frequently focuses on improving basic pragmatic skills such as requesting or on early semantic skills such as vocabulary acquisition. To address this issue, the primary goal of this study was to evaluate the effects of implementing the AAC Generative Language Intervention (AAC-GLI) program on the aided expressive grammar of preschoolers with relatively intact receptive language skills who could benefit from AAC.

A randomized controlled trial was used to evaluate the results. A total of 40 children who required AAC participated in the control group, intervention group, or both groups. The families of both the control and intervention group participants received a half-day AAC workshop. The intervention group also received 28 play-based AAC-GLI sessions. Weighted mean length of utterance in symbols (W-MLUSym), which was developed specifically for aided communicators, was used to measure progress.

The intervention group demonstrated superior effects on W-MLUSym compared with the control group. Additionally, growth modeling demonstrated that the intervention condition was a significant moderator of change over time, with children in the intervention condition having statistically significantly greater increases in W-MLUSym, while W-MLUSym for children in the control condition remained similar to baseline.

AAC-GLI can be used to teach preschoolers with a range of impairments to improve their expressive grammar skills. Providing AAC intervention that focuses on grammatical growth is an important part of expressive language development for these young children.