In the past five years, there have been significant changes concerning the material and design properties of digital books, with an impact on children's enjoyment and learning from reading on screen. Despite the rapid advances in technology, research on children's digital books is disjointed. This is because of no consistent approach to the study of interactivity, an under-theorised relationship between print and digital books, and a binary design focused on either learning or playful engagement with digital books. Drawing on the discourse reminiscent of digital game designers, some developers, scholars and professionals celebrate interactivity in digital books as a possibility to motivate and engage children in reading, while a body of experimental research documents the negative impact of interactivity on children's story comprehension and vocabulary learning. This paper presents an integrative framework based on a comprehensive literature review and a content review of the hundred most popular children's digital interactive books. The framework offers: (1) methodological guidance and a definition of interactivity based on five key categories; (2) theoretical guidance based on the third-space theory; and (3) innovative design and evaluation models based on a "method assemblage." As such, the integrative framework provides new tools and perspectives to advance the field of children's digital books.