Introduction

Expertise, by definition, refers to the manifestation of skills and understanding resulting from the accumulation of a large body of knowledge. This implies that in order to understand how experts perform and why they are more capable than non-experts, we must understand the representation of their knowledge, that is, how their knowledge is organized or structured, and how their representations might differ from those of novices. For example, if a child who is fascinated with dinosaurs and has learned a lot about them correctly infers attributes about some dinosaurs that was new to them by reasoning analogically to some known dinosaurs (e.g., the shape of teeth for carnivores versus vegetarians), we would not conclude that the “expert” child has a more powerful analogical reasoning strategy. Instead, we would conclude that such a global or domain-general reasoning strategy is available to all children, but that novice children might reason analogically to some other familiar domain, such as animals (rather than dinosaurs), as our data have shown (Chi, Hutchinson, & Robin, 1989). Thus, the analogies of domain-novice are less powerful not necessarily because they lack adequate analogical reasoning strategies, although they may, but because they lack the appropriate domain knowledge from which analogies can be drawn. Thus, in this framework, a critical locus of proficiency lies in the representation of their domain knowledge.