Associations between receptive and expressive vocabulary and early literacy in young students with intellectual disabilities using AAC.

PURPOSE: This study examined the associations between receptive and expressive vocabulary and early literacy skills (i.e., phonological awareness and letter-sound knowledge) among 39 students aged 6-14 years with intellectual disabilities, autism, and/or Down syndrome who use augmentative and alternative communication (AAC). Receptive and expressive vocabulary are identified as a key risk factor for developing reading skills in students with intellectual disabilities who use AAC.

METHODS

Spearman's correlation analyses and generalized linear models were conducted throughout this non-experimental investigation to examine the association between receptive and expressive vocabulary, phonological awareness (sound blending and initial sound recognition), and letter-sound knowledge.

RESULTS

Findings revealed a significant correlation between expressive vocabulary (i.e., words children can use in speech) and both letter-sound knowledge and sound blending, contrary to prior research. Additionally, students' receptive and expressive vocabulary showed no correlation with their early literacy skills. Binomial Generalized Linear Models (mixed-effects models) highlighted the importance of receptive vocabulary in early literacy development. Furthermore, looking at the differences within the sample, students with autism and intellectual disability requiring AAC had a higher negative probability of maximum scores in early literacy skills.

CONCLUSIONS

These findings deepen understanding of how the correlations between receptive and expressive vocabulary relate to early literacy skills. This may contribute to more targeted interventions and provide implications for practitioners and their teaching within receptive and expressive vocabulary and early literacy components, which will benefit this population in further reading development.