) and Karpicke, Butler, and Roediger (Memory, 17:471-479, 2009), have surveyed college students' use of various study strategies, including self-testing and rereading. These studies have documented that some students do use self-testing (but largely for monitoring memory) and rereading, but the researchers did not assess whether individual differences in strategy use were related to student achievement. Thus, we surveyed 324 undergraduates about their study habits as well as their college grade point average (GPA). Importantly, the survey included questions about self-testing, scheduling one's study, and a checklist of strategies commonly used by students or recommended by cognitive research. Use of self-testing and rereading were both positively associated with GPA. Scheduling of study time was also an important factor: Low performers were more likely to engage in late-night studying than were high performers; massing (vs. spacing) of study was associated with the use of fewer study strategies overall; and all students-but especially low performers-were driven by impending deadlines. Thus, self-testing, rereading, and scheduling of study play important roles in real-world student achievement.

When recalling key definitions from class materials, college students are often overconfident in the quality of their responses. Even with commission errors, they often judge that their response is entirely or partially correct. To further understand this overconfidence, we investigated whether idea-unit judgements would reduce overconfidence (Experiments 1 and 2) and whether students inflated their scores because they believed that they knew answers but just responded incorrectly (Experiment 2). College students studied key-term definitions and later attempted to recall each definition when given the key term (e.g., What is the availability heuristic?). All students judged the quality of their recall, but some were given a full-definition standard to use, whereas other students first judged whether their response included each of the individual ideas within the corresponding correct answer. In Experiment 1, making these idea-unit judgements reduced overconfidence for commission errors. In Experiment 2, some students were given the correct definitions and graded other students' responses, and some students generated idea units themselves before judging their responses. Students were overconfident even when they graded other students' responses, and, as important, self-generated idea units for each definition also reduced overconfidence in commission errors. Thus, overconfidence appears to result from difficulties in evaluating the quality of recall responses, and such overconfidence can be reduced by using idea-unit judgements.

When recalling key term definitions from class materials, students may recall entirely incorrect definitions, yet will often claim that these commission errors are entirely correct; that is, they are overconfident in the quality of their recall responses. We investigated whether this overconfidence could be reduced by providing various standards to middle school students as they evaluated their recall responses. Students studied key term definitions, attempted to recall each one, and then were asked to score the quality of their recall. In Experiment 1, they evaluated their recall responses by rating each response as fully correct, partially correct, or incorrect. Most important, as they evaluated a particular response, it was presented either alone (i.e., without a standard) or with the correct definition present. Providing this full-definition standard reduced overconfidence in commission errors: Students assigned full or partial credit to 73% of their commission errors when they received no standard, whereas they assigned credit to only 44% of these errors when receiving the full-definition standard. In Experiment 2, a new standard was introduced: Idea units from each definition were presented, and students indicated whether each idea unit was in their response. After making these idea-unit judgments, the students then evaluated the quality of their entire response. Idea-unit standards further reduced overconfidence. Thus, although middle school students are overconfident in evaluating the quality of their recall responses, using standards substantially reduces this overconfidence and promises to improve the efficacy of their self-regulated learning.

We report the results of a preregistered, cluster randomized controlled trial of a mathematics learning intervention known as interleaved practice. Whereas most mathematics assignments consist of a block of problems devoted to the same skill or concept, an interleaved assignment is arranged so that no 2 consecutive problems require the same strategy. Previous small-scale studies found that practice assignments with a greater proportion of interleaved practice produced higher test scores. In the present study, we assessed the efficacy and feasibility of interleaved practice in a naturalistic setting with a large, diverse sample. Each of 54 7th-grade mathematics classes periodically completed interleaved or blocked assignments over a period of 4 months, and then both groups completed an interleaved review assignment. One month later, students took an unannounced test, and the interleaved group outscored the blocked group, 61% versus 38%, d ϭ 0.83. Teachers were able to implement the intervention without training, and they later expressed support for interleaved practice in an anonymous survey they completed before they knew the results of the study. Although important caveats remain, the results suggest that interleaved mathematics practice is effective and feasible. Educational Impact and Implications StatementEvery school day, many millions of mathematics students complete a set of practice problems that can be solved with the same strategy, such as adding fractions by finding a common denominator. In an alternative approach known as interleaved practice, practice problems are arranged so that no two consecutive problems can be solved by the same strategy, and this approach forces students to choose an appropriate strategy for each problem on the basis of the problem itself. We conducted a large randomized classroom study and found that a greater emphasis on interleaved practice dramatically improved test scores.

The unskilled-and-unaware phenomenon occurs when low performers tend to overestimate their performance on a task, whereas high performers judge their performance more accurately (and sometimes underestimate it). In previous research, this phenomenon has been observed for a variety of cognitive tasks and judgment scales. However, the role of judgment scale in producing the unskilled-and-unaware phenomenon has not been systematically investigated. Thus, we present four studies in which all participants judged their performance on both a relative scale (percentile rank) and an absolute scale (number correct). The studies included a variety of performance tasks (general knowledge questions, math problems, introductory psychology questions, and logic questions) and test formats (multiple-choice, recall). Across all tasks and formats, the percentile-rank judgments were less accurate than the absolute judgments, particularly for low and high performers. Furthermore, in Studies 1-3, the absolute judgments were highly accurate, even when the percentile-rank judgments were not. Thus, differences in the accuracy of percentile-rank judgments across skill levels do not always represent differences in self-awareness, but rather they may arise from difficulties that performers have at evaluating how well others are performing. Most importantly, the unskilled-and-unaware phenomenon on a relative scale does not guarantee inaccurate self-evaluations of absolute performance.