Not All Planes Have Propellers: Using Context Variability to Treat Word Learning in Late TalkerWith the Vocabulary Acquisition and Usage for LTalkers Protocol

Purpose: The purpose of this study was to determine if the Vocabulary Action and Usage for Late Talkers (VAULT) intervention could be efficaciapplied to a new treatment target: words a child neither understood nor We also assessed whether the type of context variability used to encosemantic learning (i.e., action or object) would affect learning outcomes. Method: Nineteen primarily English-speaking late-talking toddlers received 8 weof VAULT intervention. They were quasirandomly assigned to a condition that lighted either object or action variability. Individual effect sizes were calculatetarget (treated) and control (not treated) words for each child. These were bined to assess group-level comparisons of treatment efficacy and treatment ditions. Generalization of the word-learning ability was assessed by comprates of learning on a vocabulary checklist prior to and during intervention. Bian statistics (e.g., t tests, analysis of variance) were used for the analyses. Results: There was strong evidence for a treatment effect showing that chproduced more target than control words and moderate evidence that understood more target than control words. There was strong evidence for eralization. Children learned an average of 6.8 words per week during treatThere was anecdotal evidence for no difference between treatment conditioConclusions: VAULT, with a focus on context variability, can be used eciously to teach children to say words they do not understand at the streatment. The effects were most pronounced in the generalization data. tionally, children were able to learn later-acquired words.