The ability to make inferences is essential for effective language comprehension. While inferencing training benefits reading comprehension in school-aged children (see Elleman, 2017, for a review), we do not yet know whether it is beneficial to support the development of these skills prior to school entry. In a pre-registered randomised controlled trial, we evaluated the efficacy of a parent-delivered intervention intended to promote four-year-olds’ oral inferencing skills during shared book-reading. One hundred children from socioeconomically diverse backgrounds were randomly assigned to inferencing training or an active control condition of daily maths activities. The training was found to have no effect on inferencing. However, inferencing measures were highly correlated with children's baseline language ability. This suggests that a more effective approach to scaffolding inferencing in the preschool years might be to focus on promoting vocabulary to develop richer and stronger semantic networks.

The present study examines the perceptual, linguistic, and social cues that were associated with preschoolers’ (4;11) growth in word-learning during shared book-reading and guided play activities. Small groups of three preschoolers (n = 30) and one adult were video-recorded during an intervention study in which new vocabulary words were explicitly taught. Adult use of taught words was coded for perceptual and linguistic cues and type of social interaction. Hearing taught words used in the book text and learning information about words’ meanings during play was positively associated with growth in word-learning. Adult use of words in responsive, or child-initiated, interactions was positively associated with word-learning growth in both book-reading and play, while adult-initiated use of words was negatively associated with word-learning growth in both settings.