The effects of literacy interventions on single-word reading for individuals who use aided AAC: a systematic review

The purpose of this systematic review was to investigate the effects of instruction on single-word reading of individuals who use aided augmentative and alternative communication (AAC). A systematic search identified nine single-case experimental design studies that involved 24 individuals who used aided AAC. Overall, the evidence indicated that instruction had positive effects on reading at the single-word level for individuals across ages and diagnostic categories (i.e., autism spectrum disorder (ASD), cerebral palsy (CP), Down syndrome, and intellectual disability). The studies revealed that these effects were consistent across a range of participant, intervention, and outcome measure characteristics. Phonological approaches, sight-word approaches, and a combination of these two approaches yielded very large effects. Despite the large effects, the findings must be viewed with caution due to limitations in the number of studies and participants and limitations in the reporting of detailed participant and intervention characteristics across the studies. In order to determine which interventions are most effective for which individuals, future research directions are discussed, including the need for greater specificity in describing participant and intervention characteristics, investigations into how to best measure intervention outcomes without requiring spoken responses, and investigations into longer-term interventions targeting a wider range of reading skills.