An experiment concerning children's conceptions of price was conducted to investigate the influence of the context of a problem on its apprehension. A total of 120 children of several age groups (nursery school, grades 2, 4, and 6) were interviewed individually. An initial question was asked ("Why does a bun cost about one Swedish crown?"), followed by a number of comparative questions ("Why does a bicycle cost more than a ball?"; "Why does a diamond ring cost more than a bicycle?"), and then a repeat of the original question. Comparison of answers to the initial question with a "best answer" judged from all the questions revealed more advanced responses on the best answer. The main changes were (1) an increment in answers expressing the idea that prices are determined by the relationship between supply and demand for commodities; and (2) a decrement in ignorant answers. This improvement seemed to be primarily in response to the comparative questions, as there was considerable regression to the initial mode of response when the initial question was repeated the second time. These results raise questions about the content-neutral nature of cognitive structures implied by Piaget's theory of cognitive stages. It is suggested that the exceptions to the stable pattern of thinking implied by Piaget's theory ought to be considered as the rule rather than the exception. (Author/SS)