ABSTRACT
This chapter briefly outlines the dominant approaches to expertise in three adjacent fields: philosophy, sociology and psychology. Even though many different forms of professional expertise exist, most theories of expertise within the field of professional education cast expertise in the same light. The chapter then investigates the relationship between professional knowledge and professional expertise. Contrary to the dominant 'fluency' accounts of expertise that are influential in education, the philosophy, psychology and sociology of expertise all suggest that professional knowledge plays an important role, alongside practice, than the education literature. The chapter also outlines how Collins's model of an 'expertise space' can be adapted to make sense of these demands and shows how different expertises differ with regards to the demands they make of professionals in terms of social skill, esoteric knowledge and tacit knowledge. Finally, it concludes by sketching an account of how one must differentiate different forms of expertise from one another in order properly to understand them.
