Problem solving: Increased planning with practice

Two experiments using two isomorphs of the Tower of Hanoi show that participants increase the amount of planning they do as they learn that it increases problem solving efficiency. In addition, competition among different approaches emerged as participants gained more experience with the task, with an optimal strategy gradually replacing a less effective, though easier one. It is hypothesized that the competition among approaches is mediated by the costs incurred in terms of the number of moves needed to solve the problems. An ACT-R model of participant performance is used to validate this hypothesized mechanism and to examine many of the details of participants’ performance. This model corresponds closely to the observed data, from overall performance in terms of number of moves to details of participants’ strategy choices and variability in strategy use among individuals.