High school (de Anda et al., 2000) and college students (Beiter et al., 2015) report feeling stressed and overwhelmed by school, struggling to balance studying, extracurriculars, and time with friends and family. In response, many are given the advice to “study smarter, not harder” to cut down on time spent on schoolwork. Yet, most students do not know how to “study smart.” In a study of undergraduate students at the University of California, Los Angeles, 80% reported they do not use study strategies taught to them, instead improvising learning techniques (Kornell & Bjork, 2007). This finding makes sense given that teachers are often told only to teach content, not study strategies, and are often under significant time pressure to fit in all the required material in a single term. Consequently, students must learn how to study on their own, often choosing methods that are ineffective because of common misconceptions about learning.
One of these misconceptions is equating learning with performance. Learning is the addition of knowledge or skills to memory whereas performance is how well someone does on a particular measure. Often, people think that because they performed well they have mastered the material, when in fact this is not always the case. For example, imagine you are trying to learn the presidents of the United States. To do this, you read a list of presidents out loud repeatedly, stopping every few minutes to quiz yourself. After an hour of intense studying, you can finally list every president without help. With your performance at 100% you decide to stop studying. The next day you retest yourself and are disappointed when you can only recall the first 10 presidents. What happened? Though at one point you were able to perform well, the material was not well-learned and so it didn’t “stick” in long-term memory. This misunderstanding can hurt students’ study strategies by leading them to stop studying too quickly or choose strategies that increase performance quickly at the expense of learning.
Another common inaccurate belief about memory is that retrieval strength and storage strength are one and the same when in fact they are quite different. Retrieval strength is how easily something is accessed in memory; in contrast, storage strength is how well something is stored in long-term memory. To illustrate this difference, try to remember your current address and the address of your childhood home. It likely took a little longer to remember your former address than your current address because your current address is higher in retrieval strength. Think of all the times in the last month you needed to remember or were reminded of your current address (i.e. mailing envelopes, paying bills, filling out your credit card information). It comes up a lot! In contrast, you probably don’t think about your former address much. Now keep these two addresses in mind and imagine that tomorrow you move to Australia. Which of the two addresses do you think you’d remember 10 years from now? Probably the address of your childhood home. That is because it has greater storage strength, and storage strength is crucial for long-term retention of information. Importantly, failing to distinguish between retrieval strength and storage strength can lead to poor study strategies because the conditions that enhance retrieval strength do not enhance storage strength. So, a student may use strategies that increase retrieval strength (like cramming the night before a midterm) at the expense of storage strength.
Because of these misconceptions, students often choose study strategies that are inefficient and ineffective, choosing things that “feel easy” (like rereading or recopying notes) than things that feel more difficult (like quizzing yourself). As a result, students spend a lot of time working on material with not much reward. Experts argue that, instead of using these unproductive methods, students should use strategies that feel more difficult and hurt short-term performance but ultimately lead to better long-term learning. These techniques are known as “desirable difficulties” (Bjork, 1994) and are evidence-based methods of effectively learning information long-term.
One desirable difficulty is spacing, which involves spreading out study sessions across a long period of time. It is often contrasted with massing, which is studying for one or two sessions over a short period of time. Studies show that spacing leads to better long-term retention of information than massing (Kapler, Weston, & Wiseheart, 2015). This benefit is at least partly due to the dynamic between retrieval strength and storage strength. During a massed study session, retrieval strength of studied information peaks, perhaps after you have reread all your notes or quizzed yourself for an hour. At that point, additional studying provides little benefit to storage strength. Spaced study sessions provide time for retrieval strength to decrease between sessions, maximizing the benefit of studying for storage strength. This is not to say that massing cannot in limited circumstances be useful. Because desirable difficulties tend to slow performance to enhance long-term learning doing a little cramming right before a test may help you do well, although you are not as likely to remember that information later.
A related desirable difficulty is interleaving. Interleaving is when you alternate your studying between two or more related concepts. For example, Kornell and Bjork (2008) asked participants to study paintings of different artists. Some saw the paintings “blocked” meaning that they saw all the paintings of one artist before moving onto the next artist. The other group saw the paintings interleaved meaning that the paintings of all the artists were presented in a mixed order. At test, participants were given a new set of paintings that they had never seen before painted by the same group of artists they had just studied and were asked to identify which artists painted which paintings. The interleaved group did better at identifying which artist painted which paintings than the blocked group, despite all participants believing that interleaving would be worse for learning than blocking. Similar findings have been found for math problems (Taylor & Rohrer, 2010) and foreign language learning (Schneider, Healy, & Bourne, 2002). It is thought that interleaving benefits learning because it encourages greater attention, promotes retrieval, and may facilitate higher-level thinking (i.e. comparing and contrasting topics).
The final desirable difficulty I will discuss is testing. Testing, as compared to restudying, has been shown to lead to better long-term learning. In a classic study by Roediger and Karpicke (2006) participants were asked to read a passage. Half of the participants were then tested on that passage whereas the other half restudied the passage. Ultimately, participants in the restudy group read the passage far more (14.2 times) than the test group (3.2 times). On a test five minutes later, participants who restudied the passage performed better than those who were repeatedly tested on it. Yet, a week later, those in the test group performed on average 20% better than those who restudied. This pattern of findings not only illustrates the power of testing, but also highlights that desirable difficulties sometime slow performance in the short-term but benefit learning at a delay.
So how do you implement these desirable difficulties in your own studying? One strategy is to make a study calendar, setting aside a little time every day or two to study for every class instead of saving all your studying for Sunday night. Another is to find ways to test yourself. Take advantage of practice tests or quizzes if they’re offered. If not, test yourself using flashcards or join a study group and get friends to quiz you. When studying, try not to focus on only one topic within a class. Unfortunately, many classes used blocked syllabi—teaching one concept before moving on, never revisiting earlier material. When studying, try to interleave by reviewing earlier concepts in between current ones. These are just suggestions; it is not yet known if there is a “right” way to use desirable difficulties. For example, we do not know yet if 48 hours between study sessions is better than 24 hours or how similar two concepts must be for interleaving to be effective. Currently, experts recommend implementing desirable difficulties where you can in your own learning. Start small, perhaps incorporating one desirable difficulty at a time. There is no magic formula to perfectly optimize learning; instead, work on adding techniques backed by science in a way that works for you.
Though I’ve focused on how desirable difficulties can be applied in traditional educational settings, desirable difficulties have been shown to aid learning in many different domains including skills such as typing (Savion-Lemieux & Penhune, 2005), bean bag throwing (Kerr & Booth, 1978), shooting free throws (Shea & Kohl, 1990), and playing tennis (Douvis, 2005). Desirable difficulties can also be applied to learning at work or everyday life. Those studying to pass a certification exam, learning a new program or filing system at work, or becoming skilled in CPR can all use desirable difficulties. In sum, desirable difficulties can be used to maximize the efficiency and potency of study or practice whenever there is a need for long-term learning.
References
Beiter, R., Nash, R., McCrady, M., Rhoades, D., Linscomb, M., Clarahan, M., & Sammut, S. (2015). The prevalence and correlates of depression, anxiety, and stress in a sample of college students. Journal of Affective Disorders, 173, 90-96.
Bjork, R. A. (1994). Memory and meta-memory considerations in the training of human beings. In J. Metcalfe, & A. Shimamura (Eds.), Metacognition: Knowing about knowing (pp. 185–205). Cambridge, MA: MIT Press.
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Douvis, S. J. (2005). Variable practice in learning the forehand drive in tennis. Perceptual and Motor Skills, 101, 531-545.
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Kerr, R., & Booth, B. (1978). Specific and varied practice of motor skill. Perceptual and Motor Skills, 46, 395-401.
Kornell, N., & Bjork, R. A. (2007). The promise and perils of self-regulated study. Psychonomic Bulletin & Review, 14(2), 219-224.
Kornell, N., & Bjork, R. A. (2008). Learning concepts and categories. Psychological Science, 19(6), 585-592.
Roediger, H. L., & Karpicke, J. D. (2006). Test-enhanced learning: Taking memory tests improves long-term retention. Psychological Science, 17(3), 249-255.
Savion-Lemieux, T., & Penhune, V. B. (2005). The effects of practice and delay on motor skill learning and retention. Experimental Brain Research, 161(4), 423-431.
Schneider, V. I., Healy, A. F., & Bourne, L. E., Jr. (2002). What is learned under difficult conditions is hard to forget: Contextual interference effects in foreign vocabulary acquisition, retention, and transfer. Journal of Memory and Language, 46(2), 419-440.
Shea, C. H., & Kohl, R. M. (1990). Specificity and variability of practice. Research Quarterly for Exercise and Sport, 61(2), 169-177.
Taylor, K., Rohrer, D. (2010). The effects of interleaved practice. Applied Cognitive Psychology, 24, 837-848.