(2006) in Charness, N., Feltovich, P, & Hoffman, R. (Eds.) Cambridge Handbook of Expertise and Expert Performance. Cambridge: Cambridge University Press
Chi, Michelene T.H.
This chapter differentiates two approaches to the study of expertise, which I call the "absolute approach" and the "relative approach," and what each implies for how expertise is assessed. It then summarizes the characteristics ways in which experts excel and the ways that they sometimes seem to fall short of common expectations.
Chi defines two approaches to defining expertise. In the "absolute approach" expertise is conceptualized as being a property of exceptional individuals who have some unique or perhaps innate talent. In the "relative approach" expertise is conceptualized in terms of comparing experts to novices. This conceptualization assumes that novices can become experts--that expertise can be learned. It is this latter approach that is particularly useful in educational terms, I think. As Chi states, "the goal [in the relative approach] is to understand how experts became that way so that others can learn to become more skilled and knowledgeable" (p. 23).
Chi goes on to identify ways in which experts excel, and ways in which they "fall short." Experts excel in the following ways: they generate the best solution, they can detect and see features that novices cannot, they spend a great deal of time analyzing problems qualitatively and develop problem representations by adding constraints within their area of expertise, they have more accurate self-monitoring skills, they are more successful at choosing appropriate strategies, they are more opportunistic that novices, and they can retrieve relevant knowledge with minimal cognitive effort. Of these characteristics, the one that is most important in my work is the ability of experts to choose appropriate strategies. I also think that the third feature--analyzing problems and situations qualitatively and applying constraints--is particular important to consider when educating teachers with the aim of helping them develop expertise. This characteristics get at the context dependence and importance of constraints on teaching situations, and their influence on strategic choice. Clearly, these characteristics of experts are not independent.
According to Chi, ways in which experts "fall short" include the fact that their knowledge is domain-limited, they can be overly confident, they sometimes fail to recall surface features and overlook details, their expertise is context-dependent within a domain, they sometimes have trouble adapting, they can be inaccurate in their prediction of novices' performance, and they can exhibit bias. In some ways, this list has more implications for thinking about expertise is teaching. For example, The idea of expert knowledge being domain-limited, and the idea that their expertise is context-dependent within a domain give rise to my dissertation research questions: What is the nature of the interaction between teaching knowledge and content knowledge? Specifically, should surveys of science teacher practice be couched within "science" or within specific scientific domains (e.g. physics, biology, etc)? Another of these characteristics that teacher educators should pay particular attention to is the idea that experts often predict novice performance inaccurately. This idea should be troubling to any teacher. Consider a physics teacher (who may be an expert problem solver) not being able to accurately predict the performance of their students. Given what we know about teaching and learning, and more specifically about formative assessment, this teacher would not be very effective.
Much has been written about expertise or expert/novice differences. This short piece by Chi provides a nice introduction and some good discussion points.