Have you ever forgotten something that you were supposed to know? Most likely you have since this occurs to all of us. Our brains not only have a great ability to learn and remember, but also to forget. Forgetting is essential, without it, we would all perhaps go insane trying to remember everything we see, hear, think, or feel every day of our lives. However, forgetting is something that we also try to constantly avoid, especially when it comes to education.
Spaced repetition has demonstrated to be efficient in interrupting the forgetting curve, which is a concept that originated from observation and research on memory and spacing effect, conducted by German psychologist Hermann Ebbinghaus in 1885, who stated that “...with any considerable number of repetitions a suitable distribution of them over a space of time is decidedly more advantageous than the massing of them at a single time.” The forgetting curve is portrayed in a graphic representation demonstrating the way in which the human brain tends to forget throughout time, the information or knowledge that we try to learn in a given time.
According to this, an average person tends to forget nearly half of what has been learned, in just a few days, unless reviews are conducted frequently. It is also suggested, that the speed at which we forget, depends on multiple factors related to the level of difficulty of the topic being studied, the way in which it is presented, and physiological issues such as stress and lack of sleep, among others.
"With any considerable number of repetitions, a suitable distribution of them over a space of time is decidedly more advantageous than the massing of them at a single time."
In order to address these problems, initiatives like “Spaced Learning” have emerged, which utilizes Spaced Repetition Systems - SRS, and considers the need to interrupt the forgetting curve at key moments throughout the educational process, hence incrementing this way the possibility for the student to remember and really learn everything studied. The most difficult concepts and materials to be learned are reminded more frequently, while those considered to be easier come up less, estimating difficulty according to the level of comfort needed by the student to generate a correct answer. This approach recognizes that the learning and memorizing capability can vary from one person to the next, it also keeps in mind that there are some subjects and topics that create more interest than others, and it focuses on repetition to avoid forgetting. Aside from spaced repetition systems, and the forgetting curve, we can find other interesting concepts that are part of this learning support methodology such as spacing effect, spaced retrieval, the necessary intervals for repetition through algorithms, and other topics related to memory, which have been considered in the development of learning solutions based on software, now that computers and mobile devices are a meaningful part of our learning environments, this allow users to personalize their cognitive process in a way that is according to their own preferences and interests.
Based on the spaced learning approach, it is necessary to conduct different reviews of the studied material with a certain frequency. It is considered that if a student reviews a topic a day later after being learned for the first time, he or she will remember 100% of what was learned, and not only 50% as it would be without reviewing it. In the same way, if a second review is done two days later, the student could remember nearly 80% of the topic, instead of 30% as the forgetting curve would suggest. If a third review is done two weeks later, it’s probable that more than 85% of the subject studied is remembered, and not just 3% as it would normally happen. On the other hand, it is estimated that if a single review is done after two weeks, students could remember up to 60% of the topic. Recent studies have determined that to implement this type of approach, it is necessary to structure well the contents, do the reviews through quick and fun tests, alternate the different topics between a review and the quick tests, and take advantage of the technological resources available to minimize the effort.
Spaced learning offers clear cognitive competitive advantages for students and it can also be implemented through simple and accessible resources such as flashcards or systems of cards with questions written on one side, and their respective answers on the other side. This approach was created by Sebastian Leitner from Germany, who proposes to review each group of cards, keeping in mind the times established in the forgetting curve and with the objective of interrupting it. This way students can manage better the times to restudy or review, revising more frequently those questions that they don’t remember well, and less frequently those that they do. This type of system can be easily implemented nowadays, through digital resources that help us save paper, storage space, and preparation time.
Even though the concept of the forgetting curve had its origins in the research about memory, carried out by German psychologist Hermann Ebbinghaus in his book “Memory; A Contribution to Experimental Psychology”, there are also more recent research works from professionals such as Dr. Erick Eich from the University of British Columbia (UBC), recognized for his contribution to cognitive science and his research work about cognitive and emotional processes, which covers diverse topics such as education, linguistics, philosophy, psychology, anthropology, and artificial intelligence; he has published multiple specialized articles and books on the subject. Another standing personality is Dr. Hal Pashler, a psychology professor at the University of California San Diego (UCSD), a distinguished researcher who is dedicated to studying human learning and memory, the mechanisms of learning and attention, and high-level visual perception; he is also the author of numerous books and articles written since 1984.
Last but not least, we’ll mention the important contributions from distinguished psychology professor from the University of California Los Angeles (UCLA), Robert A. Bjork, who coined the concept of “Desirable Difficulties” suggesting that by introducing difficulties in the learning process, long term retention of the studied material can be improved; he also directs UCLA’s Bjork Learning and Forgetting Lab, from which findings are taken from the lab into the learning environments for its implementation as methodologies to reach desired objectives. These are only some of the most noted researchers in the field of cognitive science, whose work's findings in the study of human learning and memory have contributed to understanding its potential and capability.
Research findings of the spacing effect have demonstrated among other aspects, that an adequate design of the implementation of the concept can offer effective support to learning. In the same way, it has been evident that spaced repetition is more effective than non-spaced, also that spaced learning helps minimize forgetting, and that longer review intervals are more effective; yet it has been concluded that it is possible to come to a point in which very long intervals may be counterproductive, for this reason, reviews may work better when the timing is consistent. It is also suggested that in order to increase spaced learning, it is necessary to redefine the concept of learning, for real learning does not manifest on single occasions, but instead, it must reflect a process that happens over a determined long period of time, (Thalheimer, W. -2006, February. Spacing Learning Events Over Time: What the Research Says).
Despite its rising popularity, spaced learning is also a target for criticism mostly related to the erroneous implementation of these concepts, lack of self-discipline, low levels of motivation and interest, and the amount of effort and resources needed for implementing the strategy. Even though this approach is far from a solution to all obstacles in learning, we must recognize it as an interesting alternative and complement that could help us learn better in a world overflowing with noise and information in which we all seem to be destined to forget.
In order to successfully implement this kind of approach in our own public educational settings, creative and innovative leadership is necessary, it is also essential to have an educational system that prioritizes quality in education, and that it also allows for designing proper strategies for the implementation of these type of cognitive tools, without neglecting the real needs and characteristics of our students and teachers.