Explaining inappropriate strategy selection in a simple reasoning task.

People's strategy selections appear to reflect attempts to maximize performance by selecting the most effective option for a particular task or format. Theories that account for such behaviour will be named rational models of strategy selection. However, it is possible to find instances where people are apparently biased towards using less effective strategies, and such behaviour appears to go against these models. Two experiments are reported in which participants were instructed to use first one, and then the other of two possible strategies for solving a compass point directions task (the instructed phase), and were subsequently permitted to use any strategy (the free-choice phase). A substantial minority of participants selected the less effective spatial strategy during the free-choice phase. Overall, it was found that people who rely on the spatial strategy when given a free-choice tend to be those who: (1) have not been given particular incentive to perform as well as possible; (2) have difficulty executing the better alternative, cancellation and (3) are particularly prone to making errors at the spatial strategy. Hence, although evidence was found in support of rational models of strategy selection, it is also suggested that these must additionally take account of the motivational and conceptual difficulties that people may have with a task.