This study was designed to investigate whether problem solving inefficiency in preschool children is the result of subprocess deficiencies in the children's use of logical rules and to assess the influence of 2 mnemonic components (encoding and rehearsal) on problem solving ability. The study subjects, 108 preschool children, were presented with concept discovery problems following rehearsal and coding pretraining in visual and verbal modalities. Results show that visual coding pretraining facilitated solution performance and strategy use on single outcome trials. The failure to find an increase in problem solving efficiency as a function of the coding and rehearsal conditions is discussed. (Author/SE)