Recent research in cognitive development has supported and built on Piaget’s idea that children’s active engagement with the physical and social world is a crucial component to their learning. In this chapter we offer an overview of the latest results from developmental, cognitive, computational, and educational research on children’s exploration and information search. In particular, we examine the various forms active learning can take across the life span. We start by describing the development of increasingly sophisticated forms of information solicitation in infants and preverbal children, and then draw a developmental trajectory of the effectiveness of children’s exploratory and sampling strategies as well as of their question asking. In doing so, we touch upon three main themes: Children’s sensitivity to environmental inputs, their competence as active learners, and their adaptiveness in tailoring their active learning strategies to different environmental structures. To conclude, we discuss some of the most pressing open questions and promising avenues for future developmental research on active learning and information search.