The Impact of Conversational Turn-Taking on Vocabulary Size in Toddlers With Developmental Delays Using Augmentative and Alternative Communication.

In 30 seconds

This secondary analysis of archival data from two studies examined conversational turn-taking and vocabulary during a 12-week language intervention in 109 parent–child dyads involving children with developmental delays. Children had been randomly assigned across four conditions: augmented input, augmented output, both, or spoken communication. Parent–child conversational turns followed a quadratic growth pattern, with similar patterns for parents and children. Higher conversational turn counts were associated with larger vocabulary size in dyads exposed to AAC, but this relationship was not observed in the spoken-communication condition.

Key findings

• Across the intervention, total parent–child conversational turn counts showed a quadratic growth pattern.
• Parents and children showed similar quadratic growth in conversational turns.
• Higher conversational turn counts were associated with larger vocabulary size only in dyads exposed to AAC conditions.

Why it matters

The findings suggest that conversational turn-taking may relate to vocabulary growth differently when AAC is part of intervention. For children with developmental delays, AAC may provide a context in which increased back-and-forth interaction is associated with a larger vocabulary, highlighting interaction as a relevant outcome to monitor alongside language use.

What to keep in mind

This was a secondary analysis of archival data, so the analysis was not the primary purpose of the original studies. The abstract does not report the magnitude of the vocabulary association.