Abstract
Converging evidence suggests that children's exposure to complex vocabulary during the preschool years has an impact on their later reading achievement. Yet, the most efficient way to incorporate vocabulary instruction into preschool classrooms remains an open question. The purpose of this preliminary study was to investigate effects of instructional condition on novel word learning. Four 4-year-old children participated in an adapted alternating treatments design for a total of 12 weeks. One storybook with embedded vocabulary instruction was presented each week; children either listened to a prerecorded narration under headphones (automated condition) or listened to the instructionist read aloud (instructionist-led condition). Thirty-six novel words were taught through robust vocabulary instruction, 18 in each condition. Improvement rate difference (R. I. Parker, K. J. Vannest, & L. Brown, 2009) was used as a measure of effect size. The number of words and depth to which they were learned varied considerably from participant to participant; however, consistent patterns emerged. Despite children's stated preference for the automated condition, participants generally learned more words to a greater depth in the instructionist-led condition.