Semantic knowledge can be extended in a variety of ways, including self-generation of new facts through integration of separate yet related episodes. We sought to promote integration and self-generation by providing "hints" to help 6-year-olds (Experiment 1) and 4-year-olds (Experiment 2) see the relevance of separate episodes to one…

Young children are able to categorize animals on the basis of unobservable features such as shared biological properties (e.g., bones). For the most part, children learn about these properties through explicit verbalizations from others. The present study examined how such input impacts children's learning about the properties of categories. In a…

Two studies investigated the relationship between learning names and learning concepts in preschool children. More specifically, we focused on the relationship between learning the names and learning the intended functions of artifacts, given that the intended function of an artifact is generally thought to constitute core conceptual information…

We are pleased with the commentators' thoughtful reactions to our study, as they make it clear that the study met its major goal--identifying age differences that suggest developmental changes in the learning process and the strengthening of executive processes in the second decade of life.

As the articles in this issue attest, U-shaped curves in development have stimulated a wide spectrum of research across disparate task domains and age groups and have provoked a variety of ideas about their origins and theoretical significance. In the authors' view, the ubiquity of the general pattern suggests that U-shaped curves can arise from…