An approach to learning chemical facts that starts with the periodic table and depends primarily on recognizing and completing patterns and following a few simple rules is described. This approach exploits the exceptions that arise and uses them as opportunities for further concept development.

Information-processing students solving problems in the 1960s and 1970s accepted the tradition of early experimental psychology in concentrating primarily on the study of "knowledge-lean" tasks in which competence can usually be acquired over short periods of learning and experience. In recent years, experts have examined knowledge-rich…