Spaced repetition: what is this method and main examples

Spaced repetition can change the way your students learn. It promotes long-term retention by consolidating the memorization process through active recall.

Faced with the anxiety and stress that can be caused by cramming a lot of information into a short period of time, incorporating spaced reviews helps optimize the learning process and avoid student frustration.

If you are looking for a way to improve the experience of your students or teams and maximize their results in less time, you need to know what spaced repetition is and how you can apply strategies based on this system.

What is spaced repetition?

Spaced repetition or distributed practice is a scientifically proven learning technique that helps retain information in the long term through the active retrieval of pieces of information at increasingly spaced review intervals.

The goal is to maximize learning outcomes by consolidating the memorization process, helping you remember information for longer. This allows you to beat the forgetting curve while reducing study time.

The cadence of reviews can follow pre-established patterns, such as the 2357 study model we’ll look at later, or respond to customized spacing models. It is important to adapt the pace of reviews to the learner’s needs and study objectives.

Where is the key to spaced repetition? In remembering information before it is forgotten. In other words, in creating a review schedule from day one to deepen learning and make it meaningful for the brain to remember.

Spaced repetition vs. cramming

When we talk about spaced repetition, it is inevitable to mention cramming, the opposite method if we look at their differences:

Factor	Cramming	Space repetition
Objective	Short-term academic survival. Does not promote meaningful learning.	Builds long-term knowledge. Very effective in contexts of continuous preparation.
How it works	A large amount of information is assimilated in a short period of time.	Learning takes place in a spaced manner, returning to what has been learned to prevent forgetting.
Consequences	Stress, anxiety, frustration, and virtually no long-term memory.	Less pressure, better results, and long-term retention of what has been learned.
Techniques for application in the classroom	Mass reading, last-minute summaries, study marathons, etc.	Flashcards, quizzes, customizable digital applications, etc.
Application in STEM (Science, Technology, Engineering, Mathematics)	Limited and complicated, as these are disciplines that require gradual assimilation of knowledge or strategic simplification.	Works very well in combination with microlearning, which helps to assimilate, consolidate, and recall STEM concepts.

Theoretical foundations of the spaced repetition method

The psychological principles of spaced repetition are based on studies of the learning and forgetting curves by German psychologist Hermann Ebbinghaus (1850-1909).

Ebbinghaus created lists of meaningless words he invented himself and studied how long it took him to learn them. He then noted down how much information he remembered over time (after 20 minutes, 1 hour, 1 day, etc.).

Over time, he recorded the results of how many times he studied each list, the interval between reviews, the number of words he remembered, etc.

With this data, he established what is known as the forgetting curve, a graph that shows that over time, memories deteriorate rapidly if the information is not revisited. He also discovered that forgetting is much more significant immediately after learning something. In fact, according to this psychologist, within 20 minutes, we can lose between 40% and 50% of what we have learned.

However, he also discovered that by introducing spaced repetitions into learning, forgetting can be mitigated and memory improved.

A century later, Piotr Wozniak developed the first computer implementation of the spaced repetition method based on Ebbinghaus’s findings: SuperMemo.

This system for MS-DOS allowed users to memorize information efficiently by scheduling reviews at intervals that the algorithm adjusted automatically.

Since then, SuperMemo has advanced significantly, and different learning systems and technological solutions have emerged to help students enhance their learning and overcome the forgetting curve.

Why does the spaced repetition system work?

The success of this learning strategy is based on how interrupting forgetting increases storage capacity, i.e., memories are stored optimally.

We are talking about an active learning technique, in which the student must be aware of the process and make an effort to remember and actively retrieve information.

If we compare the passage of time to a computer virus that destroys data, retrieval practice would act as an antivirus, preventing it from activating or minimizing damage.

In short, spaced repetition considers learning as a process rather than a goal.

Active recovery and educational practices

To understand why spaced repetition is one of the best learning strategies for students that you can apply in your classes, we invite you to imagine your brain as a large document filing center or a large library.

You may have a huge amount of information, but if you don’t have a cataloging system that allows you to retrieve that information, you won’t be able to find a document when you need it.

This is where long-term memory consolidation techniques such as spaced repetition come into play, acting as a document catalog in this analogy. It is therefore a really useful tool that will help you access classified information when you need it.

By incorporating this type of instructional strategy based on accessibility and retrieval of what has been learned, you will provide your students with truly effective tools to develop what is known as active memory.

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Pedagogical benefits of spaced repetition

At the pedagogical level, the benefits of spaced repetition are truly strategic for enhancing student performance:

• Reduction in cramming, and with it stress and mental fatigue. It prevents overload in students who try to learn a lot in a short period of time.
• Facilitates memory consolidation. Improves long-term information retention and enhances active recall of data. The result is better performance on assessments and assimilation of general knowledge that becomes transferable.
• Reduction in the time needed to learn thanks to improved quality of the process with a more consistent and effective routine that overcomes the forgetting curve.

In fact, according to the conclusions drawn from the article Spaced Repetition: Towards More Effective Learning in STEM (Voice & Stirton, 2020), the positive consequences of using this technique were as follows:

• Improves the academic performance of students who use it.
• Significantly increases long-term retention.
• Is more effective than the saturation caused by cramming.
• Encourages active and effective study practices such as concept retrieval and promotes deep understanding.

In addition to all these benefits, the same study highlighted the good results when applied in real STEM contexts.

Key examples of spaced repetition

Now that you know the definition of spaced repetition and its fundamentals, we want to share some practical examples of how you can apply it.

Learning a foreign language

Learning the vocabulary of a language can be frustrating at times. Memorizing lists and lists of words is as boring as it is ineffective.

To improve your results and memorize words with virtually no effort, you can follow the spaced repetition timetable below, which allows you to combine different types of activities.

Let’s use learning a new word as an example to simplify the process, but students can adapt it to phrases, complex concepts, etc.: 

Learning schedule	Task
Day 1	Learn a new word.
Day 2	Review its meaning with a flashcard on which you write the question (in this case, “What is X?”) on one side and the answer on the other. On the back, you can include some information about the term that serves as a clue.
Day 5	Recall what you have learned by constructing sentences. As much as possible, use real contexts or situations that simulate real life.
Day 10	Simulate a conversation in which the new word appears.
Day 17	Check if you are able to recall the information with tasks such as contextual translations, simulated conversation exercises, etc.

Assimilate definitions for an exam

When studying a topic for an exam, spaced repetition is a very useful technique that will help you retain information.

For example, imagine you are going to work on cell division. The review timetable could be as follows: 

Calendar	Task
Day 1	Learn what cell division is in class.
Day 3	Create a flashcard to check if you remember the concept.
Day 7	Apply the Feynman technique. This consists of trying to explain what cell division is to someone else, but in your own words and in the simplest way possible.
Day 14	Take a quiz that includes that definition.

As you can see, this memorization tool works with all types of knowledge because it allows for a high degree of adaptation, both in the type of activities that will help you retain the information and in the frequency of the reviews.

This will help you memorize mathematical formulas, historical data, improve in certain professional areas so you don’t forget protocols, work methodologies, etc. 

Spaced repetition timetable 2357

The most effective way to take advantage of the improvement in memory consolidation that the spaced repetition system can offer you is to start using it shortly after a class, rather than reviewing its content only before an exam.

The 2357 method is a proven way to enhance long-term information retention right after you’ve learned it, which, as we’ve seen, is when the highest percentage of forgetting occurs. Thanks to the effect of spacing on long-term memory, you’ll be able to avoid intensive studying or cramming and its consequences.

Here’s how the 2357 timetable works for planning your review sessions:

• 2 days after the initial learning.
• 3 days after the first review (5 days after class).
• 5 days after the second review (10 days after class).
• 7 days after the third review (17 days after class).

One of the great advantages of this system is that you can implement it in reverse if you have an exam. In that case, you should proceed as follows:

• Schedule a review session the day before the exam.
• Two days before that session, plan another one.
• Three days before that, schedule another session.
• Five days after the last session, schedule another one.
• 7 days before this third review, note down the date when you will start your spaced review.

If you don’t want to keep track of the calendar, you can use apps that you can install on your devices, or you can add the reviews to your digital calendar and activate reminders for the days when you need to review.

Leitner spaced repetition system

One of the easiest ways to introduce spaced repetition is by using a spaced repetition system (SRS) such as the 2357 model we just shared with you, or by using what is known as the Leitner system.

This method is ideal for combating boredom in your study routine because of the creative component it adds. Here are the steps you need to follow to apply it right now.

Create flashcards to promote microlearning

Breaking down a concept, topic, or practice into smaller parts makes learning easier. This is known as microlearning.

Since the pieces of information are smaller, it is easier to retain them and incorporate more data as you consolidate what you have learned.

Study cards are therefore a fantastic resource for jotting down what you need to learn, concept by concept.

They are very easy to make: on the front, write a question and on the back, write the correct answer or clues to help you get there.

Set up review boxes

This step is the heart of your Leitner system. It consists of creating small boxes (they can also be envelopes). The number of boxes depends on how many study cards you have and how much review you need.

Keep in mind that each box represents the frequency with which you need to review.

To illustrate what we have just discussed, let’s look at an example with four boxes: the first contains what you need to review every day, the second every week, the third every 15 days, and finally, the fourth every month.

As we have mentioned, the number of boxes, cards, and your study schedule can be adapted, so you can also use the 2357 schedule or any other schedule according to your pace, the nature of the subject being studied, etc.

Start applying it

As you answer the flashcards in each envelope or box correctly, they move on to the next one, so that you gradually space out your study.

In other words, on the first day, you work on the flashcards in the first box (the rest of the boxes are empty). The questions you know are moved to the second box. When it’s time to open this box, you proceed in the same way: you check your knowledge and the questions you have passed are moved to the third box, and so on.

What happens to the flashcards you get wrong? Well, instead of moving forward, they go back, and you have to work on them again until they can go to the next box.

When to use spaced repetition?

Spaced repetition is the answer to how to study effectively, avoiding the stress of having to assimilate a large amount of data in a short time and the frustration of trying to retrieve information that, despite having paid attention in class, has been lost in your memory, and you don’t know how to retrieve it.

In this sense, you and your students can use this learning technique when:

• You want to remember something for the long term and reduce forgetting, such as learning a new language, preparing for an exam, or studying technical and complex topics.
• After each class in which you have learned something new, it is best to review within 48-72 hours.
• You want to improve your results at your own pace. This is very practical in continuing education, for example.

As a teacher, this method will allow you to improve your students’ experience and help them achieve more efficient learning if you incorporate it into low-difficulty cumulative quizzes or regular review sessions to accompany your students, both in K-12 and high school programs.

In fact, according to theorists such as Kang (2016), early exposure to spaced repetition can help develop essential skills in self-regulated learning.

Its benefits are even more significant in higher education, especially in disciplines that require a high memory capacity such as technology, law, engineering, mathematics, etc.

Tips for teachers and students to maximize the benefits of spaced repetition

The effectiveness of spaced repetition lies not only in what is studied, but also in how it is studied.

For this reason, the following recommendations will help you implement this technique in the classroom and enhance your students’ results.

How to make effective flashcards

If you want your students to learn how to make effective flashcards, consider these tips based on cognitive science principles:

• Add one idea per flashcard, and make sure it is clear and short.
• Ask an open-ended question and avoid multiple choices so that students use active recall rather than recognition.
• Add examples or context to your question to facilitate information retrieval.
• Use images or graphic content in subjects such as anatomy, geography, languages, etc. This helps activate visual memory.
• Vary the type of question to avoid boredom and enhance mental connections.
• Organize your cards by grouping them into topics or blocks if you are reviewing for an exam or need to assimilate a large amount of data.
• Create a specific group of cards that brings together the questions you don’t usually get right so you can work on them in more depth.

When working with these cards, it is a good idea for students to try to answer the question before looking at the answer, as this is an active learning methodology that requires conscious participation on the part of the student.

Technological tools for applying spaced repetition in the classroom

Technology offers many solutions to make your classes more dynamic and improve them. Focusing on the spaced repetition system, a very interesting platform for educators and students is The Learning Scientists. It is a scientific dissemination site that promotes the use of flashcards as a key tool.

Beyond this website, here are some of the most popular spaced repetition-based applications that are also easy to use.

Anki

This is an application for creating flashcards based on the SuperMemo algorithm that we mentioned at the beginning of this article.

It is an ideal solution for students who want to control their own revision system. It offers many customization options and is very flexible.

Quizlet

With this application, you can train your memory with flashcards and tests. It also allows you to create study programs and offers free classroom games such as Quizlet Live.

It allows you to review in SRS mode and is well suited to K-12 students.

Brainscape

This app has a series of pre-designed flashcards for all kinds of subjects, but it also allows you to create custom cards so you can set your own optimal review intervals.

It is very useful for promoting self-directed learning or for working in class.

Assessment in spaced repetition system

Spaced repetition is, as we have discovered, a learning method based on systematic review at intervals, which is the opposite of cramming.

The result is meaningful, long-term learning that beats the forgetting curve, as supported by multiple studies in cognitive science and neuroeducation.

One of its great advantages is that it can be adapted to all levels, in classrooms, universities, or professional training.

One way to ensure that these practices have a real and lasting impact is to combine them with tailored, flexible, and secure continuous assessment systems.

This makes it necessary to promote ethical, student-centered practices, creating environments that respect their privacy and ensure a level playing field for all users.

In this context, Smowltech’s proctoring plans can offer you everything you need to create fair and secure remote assessments, as well as providing objective reports on each session to reinforce the assessment.

Request a free demo and discover how well-designed remote supervision can improve your students’ experience and strengthen their confidence in your training programs.