This chapter differentiates two approaches to the study of expertise, which I call the “absolute approach” and the “relative approach,” and what each approach implies for how expertise is assessed. It then summarizes the characteristic ways in which experts excel and the ways that they sometimes seem to fall short of common expectations.
Two Approaches to the Study of Expertise
The nature of expertise has been studied in two general ways. One way is to study truly exceptional people with the goal of understanding how they perform in their domain of expertise. I use the term domain loosely to refer to both informal domains, such as sewing and cooking, and formal domains, such as biology and chess. One could choose exceptional people on the basis of their well-established discoveries. For example, one could study how Maxwell constructed a quantitative field concept (Nersessian, 1992). Or one could choose contemporary scientists whose breakthroughs may still be debated, such as pathologist Warren and gastroenterologist Marshall's proposal that bacteria cause peptic ulcers (Chi & Hausmann, 2003; Thagard, 1998; also see the chapters by Wilding & Valentine, Chapter 31, Simonton, Chapter 18, and Weisberg, Chapter 42).
Several methods can be used to identify someone who is truly an exceptional expert. One method is retrospective. That is, by looking at how well an outcome or product is received, one can determine who is or is not an expert.