to reflect on and monitor one’s own thinking, termed “metacognition,” is a hallmark of expertise. Metacognition, like expertise, is domain-specific. That is, a particular metacognitive strategy that works in a particular activity (e.g., predicting outcomes, taking notes) may not work in others. However, metacognition is not exclusive to experts; it can be supported and taught. Thus, even for young children and older novices engaged in a new domain or topic of interest, metacognition can be an important means of controlling their own learning.⁵ Accordingly, as a means of directing and promoting learning, metacognition may have special importance in informal settings, in which learning is self-paced and frequently not facilitated by an expert teacher or facilitator.

These facets of learning—the development of expertise, the role of intuitive ideas and prior knowledge in gaining deep understanding, and the ability to reflect on one’s own thinking—can be put to use in informal settings to build deeper, more flexible understanding. One way this is accomplished is by creating informal envi-