Abstract
A crucial step in problem solving is the retrieval of already learned schemata from long-term memory, a process which may be facilitated by categorization of the problem. The way knowledge is organized affects its availability, and, at the same time, it constitutes the important difference between experts and novices. The present study employed concept maps in a novel way, as a categorization tool for chemical equilibrium problems. The objective was to determine whether providing specific practice in problem categorization improves student achievement in problem solving and in conceptual understanding. Two groups of eleventh-grade students from two special private seminars in Corfu island, Greece, were used: the treatment group (N = 19) and the control group (N = 21). Results showed that the categorization helped students to improve their achievement, but the improvement was not always statistically significant. Students at lower (Piagetian) developmental level (in our sample, students at the transitional stage) had a larger improvement, which was statistically significant with a high effect size. Finally, Nakhleh’s categorization scheme, distinguishing algorithmic versus conceptual subproblems in the solution process, was studied. Dependency of problem solving on an organized knowledge base and the significance of concept mapping on student achievement were the conclusion.