Practice and feedback effects on the confidence-accuracy relation in eyewitness memory.

It has been claimed that the lack of a reliable confidence-accuracy relation in eyewitness memory stems from eyewitnesses' lack of knowledge concerning their relative expertise. Two studies tested this idea by contrasting the effects of practice alone with practice with feedback in three successive eyewitness tests. Experiment 1 tested recall for events, and Experiment 2 used recognition of faces as test materials. Both studies showed that practice alone did not increase the confidence-accuracy relation, but practice with feedback on relative performance produced robust increases in the confidence-accuracy relation. This suggests that lack of calibration is one factor that causes the reported lack of association between confidence and accuracy for eyewitness memory.