ABSTRACT
This chapter considers traditional theories of expertise that focus on higher order strategies and on the development of a larger knowledge base. It examines the ability of experts to perceive things that novices and journeymen cannot detect, in order to determine how these “perceptual” abilities can be used to assess proficiency level and to drive training requirements. The ability to judge typicality enables experts to perform more effectively and efficiently than journeymen. The ability to judge typicality should enable people to detect when expectancies are violated. The use of typicality judgments is important for problem solving as well as decision making. Experts are particularly better than novices and journeymen in making fine perceptual discriminations. Experts can visualize how a situation developed into its current state, and they can visualize how it will continue to develop.
