The main objective of this thesis is to investigate word learning from written context in early childhood, with a focus on the effects of book format, scaffolding features, and child characteristics. There is consensus that written language provides unique opportunities to foster children’s vocabulary development. Yet, early literacy experiences are rapidly changing, with e-books and digital reading environments becoming increasingly common. Prior research investigating the effect of book format on word learning in young children has reported inconsistent findings, as synthesised in a recent meta-analysis. Given the pivotal role of early vocabulary for later reading comprehension, academic achievement, employment, and well-being, it is critical to unpack the effects of book format, scaffolding features, and their interaction with child characteristics in shaping vocabulary acquisition from written context.
Chapter 1 provides an introduction, thesis rationale, and an overview of the literature and theories relevant to the empirical work presented across chapters 2, 3, and 4. Chapter 2 reports a pre-registered study investigating the effects of book format and child characteristics on word learning via naturalistic shared reading. Chapter 3 provides an in-depth evaluation of caregivers’ scaffolding during shared reading. The focus of this pre-registered study was to test the generalisability of the fine-tuning hypothesis, that is, whether caregivers adjust their communication to their child’s individual lexical knowledge and whether this adjustment supports children’s word learning in the context of shared reading. Caregivers’ scaffolding behaviour in print- and digital-based shared reading was also compared. Chapter 4 reports a pre-registered study using a big data approach to investigate the associations between child and item characteristics, use of vocabulary scaffolds, and reading comprehension in a digital environment. Finally, Chapter 5 discusses the implications of these findings for theory and practice, along with the recommendations and directions for future research.