Both explanation and exploration can foster causal learning, yet the mechanisms underlying these effects are largely unknown, especially in early childhood. In this article, I provide an overview of research on the relation among explanation, exploration, and the development of scientific reasoning. I propose that explaining and exploring operate in tandem as hypothesis‐generating and hypothesis‐testing mechanisms. I review evidence that supports this claim by demonstrating that inconsistency with prior knowledge selectively motivates children to construct explanations, guides discovery‐oriented behavior, and drives the early‐developing capacity to reason scientifically. I conclude with a discussion of the educational applications of research on the development of children's scientific reasoning in informal learning settings.