Effect of Verbal Routine Contexts and Expansions on Gains in the Mean Length of Utterance in Children With Developmental Delays

Abstract

This study tests the hypothesis that verbal routines and expansions increase generalized child mean length of utterance (MLU). Verbal routines were built through repeated interaction with the same picture book across several intervention sessions. The subjects were four young children with developmental delay. One of the subjects experienced two rounds of the intervention (i.e., two intervention phases with two different books) to provide the opportunity for more replication and extension of the effects. Generalization sessions were conducted with a different adult, different modality of material (i.e., objects), and different interaction style than were used during the intervention. The pattern of the results provides strong evidence that the intervention increased generalized MLU in children in the first stage of language development more than in children in a later language stage. The secondary analyses support the notion that verbal routines and expansions were responsible for the effects. Future research is needed to determine why the intervention was not effective for the developmentally older cases but was effective for the developmentally younger cases.