Students often are overconfident when they predict their performance on classroom examinations, and their accuracy often does not improve across exams. One contributor to overconfidence may be that students did not have enough experience, and another is that students may under-use their knowledge of prior exam performance to predict performance on their upcoming exams. To evaluate the former, we examined student prediction accuracy across 13 exams in an introductory course on educational psychology. For the latter, we computed measures that estimate the extent to which students "use" the prior exam score when predicting performance and whether students "should" use the prior exam scores. Several outcomes are noteworthy. First, students were overconfident, and contrary to expectations, this overconfidence did not decline across exams. Second, students' prior exam scores were not related to subsequent predictions, even though prior exam performance showed little bias with respect to predicting future performance. Thus, students appear to under-use prior performance despite its utility for improving prediction accuracy about future exam performance.