Prediction and evaluation errors of self-performance (overestimation and underestimation) occasionally bring serious consequences. This study examined possible causes for overestimation and underestimation using a newly devised experimental paradigm. The experiment comprised two sessions: in the first session, participants learned rules for button presses in response to particular combinations of digits, and in the second session, they performed a similar task with the same rules but in response to English letters and they were randomly assigned to one of three tasks with different button configurations: Sequential, Reversed, and Partially reversed. The participants predicted and evaluated their performance before and after each session, respectively. It was found that participants tended to overestimate both predictions and evaluations of performance on the Partially reversed task. These results suggest that differential changes in stimulus-response association lead to differentially biased estimations. In particular, people might underestimate the switching costs from ordinal to non-ordinal representation.
