It’s the talk that counts: A review of how the extra-textual talk of caregivers during shared book reading with young children has been categorized and measured

Extra-textual talk (ETT), the spontaneous conversation that occurs alongside the text read aloud during book reading is a common but also critically important feature of shared reading that cultivates interactions and supports the language development of young children. This exploratory review of 45 papers describing observations and measures of spontaneous ETT in parent-and-child dyadic shared reading from 1977 to 2022 illustrates the varying methods of categorization and measurement of the ETT have been used. The purpose of this review was to organize and consolidate this large collection of previous research to address two research questions. First, how can current researchers and practitioners organize this array of systems for measuring and categorizing ETT proposed by past researchers? Across the studies reviewed, three primary approaches for measuring or categorizing parents’ spontaneous ETT were found based on (1) content, (2) overall reader style, or (3) quantity-based measures of volume and complexity. Secondly, this review addressed what specific factors researchers have tested for their impact on extra-textual talk during shared reading. The three major influences on ETT come from variability among (1) readers, (2) children, and (3) the books being shared in support of a triangular model of shared book reading. The specific subcategories used in typing and measuring ETT, as well as the subfactors of those variables that may affect it are discussed.