Theories of problem solving have examined a variety of strategies through which individuals reach solutions to different problems. Problem-solving researchers approach solvers' success with a problem either as the result of special thinking processes or as the product of ordinary cognitive processes like comprehension and memory. Despite their focus on the construction of effective solution strategies, however, current problem solving and creativity theories have not adequately examined how the solver's knowledge and experience are implicated in the formation and implementation of those strategies. This book argues that the structure and function of the individual's conceptual system is a crucial aspect of problem solving. In particular, this work presents theoretical and empirical accounts regarding the flexibility with which individuals perform numerous categorizations when constructing plans for action, which could provide a valuable model for explaining problem-solving phenomena. Thus, this book approaches problem solving as a dynamic expression of goal-directed cognition.