Direct Instruction Improves Word Learning for Children With Developmental Language Disorder

The current study compared the effects of direct instruction versus indirect exposure on multiple aspects of novel word learning for children with developmental language disorder (DLD) and children with typical language development (TLD).

Participants included 36 children with DLD and 45 children with TLD. All children were in the first grade and 6-8 years of age (Mdn = 7 years; 2 months). Using a between-subjects design, children were randomly assigned to be exposed to novel words and their unfamiliar referents via either direct instruction (each referent presented in isolation with an explicit goal of learning) or indirect exposure (multiple referents presented with the goal of answering yes/no questions).

In alternative forced-choice measures of recognition, children with DLD were less accurate than their TLD peers in linking words to referents, encoding semantic categories for words, and encoding detailed representations of word forms. These differences in word learning were accounted for by a constellation of cognitive measures, including receptive vocabulary, phonological memory, visuospatial memory, and sustained attention. All children were similarly accurate in retaining word forms over a 24- to 48-hr delay. Children with TLD were more accurate in all aspects of word learning following direct instruction compared to indirect exposure. Benefits from direct instruction were observed for children with DLD in link and semantic, but not word form, learning.

These results suggest that vocabulary interventions with direct instruction can help children with DLD learn some, but not all, aspects of novel words. Additional support is necessary to help children with DLD encode rich phonological representations.