Jeffrey D. Karpicke

The Power of Testing Memory: Basic Research and Implications for Educational Practice:

A powerful way of improving ones memory for material is to be tested on that material. Tests enhance later retention more than additional study of the material, even when tests are given without feedback. This surprising phenomenon is called the testing effect, and although it has been studied by cognitive psychologists sporadically over the years, today there is a renewed effort to learn why testing is effective and to apply testing in educational settings. In this article, we selectively review laboratory studies that reveal the power of testing in improving retention and then turn to studies that demonstrate the basic effects in educational settings. We also consider the related concepts of dynamic testing and formative assessment as other means of using tests to improve learning. Finally, we consider some negative consequences of testing that may occur in certain circumstances, though these negative effects are often small and do not cancel out the large positive effects of testing. Frequent testing in the classroom may boost educational achievement at all levels of education.

Retrieval Practice Produces More Learning than Elaborative Studying with Concept Mapping

Two different ways of thinking through texts are compared for learning value. Educators rely heavily on learning activities that encourage elaborative studying, whereas activities that require students to practice retrieving and reconstructing knowledge are used less frequently. Here, we show that practicing retrieval produces greater gains in meaningful learning than elaborative studying with concept mapping. The advantage of retrieval practice generalized across texts identical to those commonly found in science education. The advantage of retrieval practice was observed with test questions that assessed comprehension and required students to make inferences. The advantage of retrieval practice occurred even when the criterial test involved creating concept maps. Our findings support the theory that retrieval practice enhances learning by retrieval-specific mechanisms rather than by elaborative study processes. Retrieval practice is an effective tool to promote conceptual learning about science.

Metacognitive strategies in student learning: do students practise retrieval when they study on their own?

Basic research on human learning and memory has shown that practising retrieval of information (by testing the information) has powerful effects on learning and long-term retention. Repeated testing enhances learning more than repeated reading, which often confers limited benefit beyond that gained from the initial reading of the material. Laboratory research also suggests that students lack metacognitive awareness of the mnemonic benefits of testing. The implication is that in real-world educational settings students may not engage in retrieval practise to enhance learning. To investigate students’ real-world study behaviours, we surveyed 177 college students and asked them (1) to list strategies they used when studying (an open-ended free report question) and (2) to choose whether they would reread or practise recall after studying a textbook chapter (a forced report question). The results of both questions point to the same conclusion: A majority of students repeatedly read their notes or textbook (despite the limited benefits of this strategy), but relatively few engage in self-testing or retrieval practise while studying. We propose that many students experience illusions of competence while studying and that these illusions have significant consequences for the strategies students select when they monitor and regulate their own learning.

Expanding retrieval practice promotes short-term retention, but equally spaced retrieval enhances long-term retention

Expanding retrieval practice (T. K. Landauer & R. A. Bjork, 1978) is regarded as a superior technique for promoting long-term retention relative to equally spaced retrieval practice. In Experiments 1 and 2, the authors found that expanding retrieval practice of vocabulary word pairs produced short-term benefits 10 min after learning, conceptually replicating Landauer and Bjorks results. However, equally spaced retrieval produced superior retention 2 days later. This pattern occurred both with and without feedback after test trials. In Experiment 3, the 1st test occurred immediately or after a brief delay, and repeated tests were expanding or equally spaced. Delaying the first test improved long-term retention, regardless of how the repeated tests were spaced. The important factor for promoting long-term retention is delaying initial retrieval to make it more difficult, as is done in equally spaced retrieval but not in expanding retrieval. Expanding the interval between repeated tests had little effect on long-term retention in 3 experiments.

The effect of type and timing of feedback on learning from multiple-choice tests

Two experiments investigated how the type and timing of feedback influence learning from a multiple-choice test. First, participants read 12 prose passages, which covered various general knowledge topics (e.g., The Sun) and ranged between 280 and 300 words in length. Next, they took an initial six-alternative, multiple-choice test on information contained in the passages. Feedback was given immediately for some of the multiple-choice items or after delay for other items. Participants were either shown the correct answer as feedback (standard feedback) or were allowed to keep answering until the correct answer was discovered (answer-until-correct feedback). Learning from the test was assessed on a delayed cued-recall test. The results indicated that delayed feedback led to superior final test performance relative to immediate feedback. However, type of feedback did not matter: discovering the correct answer through answer-until-correct feedback produced equivalent performance relative to standard feedback. This research suggests that delaying the presentation of feedback after a test is beneficial to learning because of the spaced presentation of information.

Correcting a Metacognitive Error: Feedback Increases Retention of Low- Confidence Correct Responses

Previous studies investigating posttest feedback have generally conceptualized feedback as a method for correcting erroneous responses, giving virtually no consideration to how feedback might promote learning of correct responses. Here, the authors show that when correct responses are made with low confidence, feedback serves to correct this initial metacognitive error, enhancing retention of low-confidence correct responses. In 2 experiments, subjects took an initial multiple-choice test on general knowledge facts and made a confidence judgment after each response. Feedback was provided for half of the questions, and retention was assessed by a final cued-recall test. Taking the initial test improved retention relative to not testing, and feedback further enhanced performance. Consistent with prior research, feedback improved retention by allowing subjects to correct initially erroneous responses. Of more importance, feedback also doubled the retention of correct low-confidence responses, relative to providing no feedback. The function of feedback is to correct both memory errors and metacognitive errors.

Retrieval-Based Learning: Active Retrieval Promotes Meaningful Learning

Retrieval is the key process for understanding learning and for promoting learning, yet retrieval is not often granted the central role it deserves. Learning is typically identified with the encoding or construction of knowledge, and retrieval is considered merely the assessment of learning that occurred in a prior experience. The retrieval-based learning perspective outlined here is grounded in the fact that all expressions of knowledge involve retrieval and depend on the retrieval cues available in a given context. Further, every time a person retrieves knowledge, that knowledge is changed, because retrieving knowledge improves one’s ability to retrieve it again in the future. Practicing retrieval does not merely produce rote, transient learning; it produces meaningful, long-term learning. Yet retrieval practice is a tool many students lack metacognitive awareness of and do not use as often as they should. Active retrieval is an effective but undervalued strategy for promoting meaningful learning.

Spaced Retrieval: Absolute Spacing Enhances Learning Regardless of Relative Spacing.

Repeated retrieval enhances long-term retention, and spaced repetition also enhances retention. A question with practical and theoretical significance is whether there are particular schedules of spaced retrieval (e.g., gradually expanding the interval between tests) that produce the best learning. In the present experiment, subjects studied and were tested on items until they could recall each one. They then practiced recalling the items on 3 repeated tests that were distributed according to one of several spacing schedules. Increasing the absolute (total) spacing of repeated tests produced large effects on long-term retention: Repeated retrieval with long intervals between each test produced a 200% improvement in long-term retention relative to repeated retrieval with no spacing between tests. However, there was no evidence that a particular relative spacing schedule (expanding, equal, or contracting) was inherently superior to another. Although expanding schedules afforded a pattern of increasing retrieval difficulty across repeated tests, this did not translate into gains in long-term retention. Repeated spaced retrieval had powerful effects on retention, but the relative schedule of repeated tests had no discernible impact.

Retrieval-based learning: An episodic context account.

Abstract Practicing retrieval is a powerful way to promote learning and long-term retention. This chapter addresses the theoretical underpinnings of retrieval-based learning. We review methodological issues in retrieval practice research, identify key findings to be accounted for, and evaluate current candidate theories. We propose an episodic context account of retrieval-based learning, which explains retrieval practice in terms of context reinstatement, context updating, and restriction of the search set. Retrieval practice involves attempting to reinstate a prior learning context, and when retrieval is successful, the representation of context is updated to include features of retrieved contexts and the current context. Future retrieval is enhanced because updated context representations can be used to restrict the search set and hone in on a desired target. The context account accommodates a wide variety of phenomena in the retrieval practice literature and provides a comprehensive and cohesive account of retrieval-based learning.

When and why do retrieval attempts enhance subsequent encoding

Unsuccessful retrieval attempts can enhance subsequent encoding and learning. In three experiments, subjects either attempted to retrieve word pairs prior to studying them (e.g., attempting to recall tide–? before studying tide–beach) or did not attempt retrieval and retention of the studied targets was assessed on a subsequent cued recall test. Experiment 1 showed that attempting retrieval enhanced subsequent encoding and recall relative to not attempting retrieval when the word pairs were semantically related, but not when the pairs were unrelated. In Experiment 2, studying a different word pair prior to the correct pair (e.g., studying tide–wave prior to tide–beach) did not produce the same effect as attempting retrieval prior to studying. Constraining retrieval to a particular candidate word prior to study (e.g., recalling tide–wa__ before studying tide–beach) produced a negative effect on subsequent recall. Experiment 3 showed that attempting retrieval did not enhance encoding when a brief delay occurred between the retrieval attempt and the subsequent study trial. The results support the idea that a search set of candidates related to the retrieval cue is activated during retrieval and that this retrieval-specific activation can enhance subsequent encoding of those candidates.