Learning words during shared book reading: The role of extratextual talk designed to increase child engagement.

Shared book reading (SBR) is a valuable context for word learning during early childhood, and adults' extratextual talk boosts the vocabulary building potential of SBR. We propose that the benefits of such talk depend largely on a reader's success in promoting children's active engagement (attention and interest) during SBR. When readers ask children questions about new words, especially if they respond to children in a prompt, contingent, and appropriate (positive) manner, this verbal responsiveness functions as an effective engagement strategy. We randomly assigned 3- and 4-year-olds to three reading conditions (low, moderate, and high) distinguished by the degree to which the reader used extratextual engagement strategies, including verbal responsiveness. Despite equal exposure to unfamiliar target words, children's performance improved on two measures of word learning across the three conditions, demonstrating the value of engagement strategies in extratextual talk. This study provides a strong experimental demonstration that adult verbal responsiveness directly benefits preschoolers' word learning.