Why do we retain information better when we learn it over a long time period?

The 

Spacing Effect

, explained.
Bias

What is the Spacing Effect?

The spacing effect demonstrates that learning is more effective when repeated in spaced-out sessions. By repeating and spacing out information individuals learn, they can better recall that information in the future.1

Where this bias occurs

The spacing effect is broadly applicable to many fields, notable in examples of education and business. A typical example of the spacing effect can be seen in different ways students study for courses and exams.

The spacing effect occurs when information is repeatedly learned over a spaced-out long period, resulting in an individual being about to recall better and remember the information being learned. The effect demonstrates that more information is encoded into our long-term memory, when studied in spaced-out sessions, a process commonly referred to as spaced repetition. Students who use flashcards and have study techniques that extend over long periods are utilizing the spacing effect to learn.2 This contrasts with retaining information by massed presentation — a study habit more commonly referred to as cramming, which is the act of intensely absorbing large amounts of information in a short period.2

Debias Your Organization

Most of us work & live in environments that aren’t optimized for solid decision-making. We work with organizations of all kinds to identify sources of cognitive bias & develop tailored solutions.

Learn about our work

Individual effects

The spacing effect can ensure that individuals can better recall and learn information. Even though this memory technique has been studied extensively and has been proven to improve individuals’ learning capabilities, the spacing effect is still not widespread in schooling systems. Schools do encourage study habits that align with the spacing effect, but not to the desired extent of many experts. By teaching the spacing effect, both students and adults could benefit from learning how to learn better. 

In contrast, corporations can use advertisements to capitalize on the spacing effect. For example, companies will place advertisements so individuals are able to better remember their product or service. We remember ads that are strategically placed and spaced out, even though their products might not be the best or most reliable.3 By this logic companies will place ads not one after the other throughout a television program, but rather spaced apart, leading us to remember the products better than we would initially.

Systemic effects

By failing to incorporate the spacing effect in school systems globally, the education system is missing a pivotal opportunity to teach students how to learn effectively1,2. Cramming techniques, which are popular among students, do not lead to long-term learning. Learning through cramming and memorization is tedious and ineffective.

Why it happens

Years of research on memory and our ability to recall information have led to many theories for why the spacing effect occurs. Potential reasons for the spacing effect include the following:

Forgetting and learning are Linked

When individuals review close to the point of nearly forgetting, our brains reinforce the memory and add new detail. This is why teaching others, and writing practice papers are effective ways for students to revise and highlight what’s been forgotten in their own learning.3

Retrieving memories changes the way they are later encoded 

Practice tests are an effective method of studying because of their level of difficulty. Difficulty makes individuals recall information instead of just recognizing it when studying. The harder it is to remember a piece of information while practicing it, the better it will be retained or recalled later. The more strain it takes to remember information initially, the more mental labor an individual causes themselves, resulting in the action of recalling being more natural in the future.4

Great importance assigned to repeated information 

The information an individual encounters on a regular basis becomes effortless to recognize in the future. An example of this includes an individual’s telephone number, directions to work, or names of coworkers. Though from time to time an individual may forget these things, because they are repeated so often, they are typically easy for individuals to access and remember. 

Semantic priming

The associations people form between words also has been speculated to impact the spacing effect. Semantic priming describes why it’s easier to remember words or sentences linked or connected to one another. For example, the sentence “the nurse and the doctor go to the hospital,” is easier to remember than “the artist and the driver go to the supermarket”. This is because, in the first sentence, nurse, doctor, and hospital are linked, making it easier to remember. It’s also been theorized that repetition over time primes individual’s to make connections to information or words in sentences.5

Why it is important

The spacing effect can be used effectively by individuals, to better learn and retain information. Improving our memory and learning throughout our life, can greatly help us succeed. By capitalizing on the cognitive benefits of the spacing effect, and incorporating effective learning processes, we can better ourselves, our decision-making abilities, and our learning capabilities.

How to activate it

By being aware of the spacing effect, individuals can use it to our advantage. By effectively utilizing the spacing effect to better ourselves for work or school, we can take advantage of this cognitive effect and improve our daily lives. The spacing effect can be activities in the following ways: 

Schedule information review 

The act of scheduling period for information reviews, typically follows a hierarchy review process, such as going over information after an hour, a day, then every other day, weekly, monthly, and so on. By planning and scheduling these reviewing sessions, you can enforce the spacing effect into your learning habits and process.

Store and organize information

The use of flashcards, or spaced repetition software such as Anki and SuperMemo, are standard tools to help individual’s practice integrating the spacing effect in their learning. Softwares like those mentioned above aid in providing a schedule for individual’s to follow and give the advantage of requiring little effort on the individual’s part to maintain.

Create a metric for tracking progress

Additionally, space repetition techniques and systems have been found to work best when including forms of positive reinforcement. Applications like Duolingo incorporate positive reinforcement in their learning processes, by similarly using a points system to motivate users to practice languages and improve continuously. Tracking progress can give individuals a sense of improvement and achievement, motivating them to continue learning.

Create set durations for review processes

Finally, limiting our practicing time is essential when using the spacing effect. When individuals practice for too long, their attention spans are likely to waver, resulting in a decreased amount of retained information. A typical recommendation for learning sessions is 30 minutes long, with breaks to split up these sessions.4

How it all started

The spacing effect has been referred to as one of the oldest, and best-documented phenomena in the history of learning and memory research.6 The origin of the spacing effect was first identified by German psychologist Herman Ebbinghaus. Herman Ebbinghaus is known as a pioneer in the field of quantitative memory research, with his most important findings in areas of forgetting and learning curves.4 Herman Ebbinghaus first detailed the spacing effect in his published book Memory: A Contribution to Experimental Psychology in 1885. The book outlined that individuals forget 80% of newly learned information within 24 hours.7

When researching human memory capabilities, and what causes individuals to forget, he coined something called the forgetting curve. The forgetting curve is a curve that describes the percentage of learned knowledge, which individuals can recall and reproduce plotted against time. The recurrence scheme developed by Herman Ebbinghaus demonstrated how individuals could store information in long-term memory.

From this research, Herman Ebbinghaus founded the vital principle of the spacing effect. To alter the forgetting and learning curves, individuals would have to store information in their long-term memory, which he noted was effectively done by repeating information within certain intervals.7 

Example 1 - Studying

An example of the spacing effect is notable in education and learning. Though it is commonly accepted that the spacing effect and repetition produce significant learning gains for individuals, most textbooks are written in discrete chapters, which do not enforce repetition of the subject throughout. To test an alternative, in 2006, Dr. Rohrer created a two-part study where sets of students were taught how to solve math problems.8

In the first part of the experiment, students either used massed or spaced practice to study and solve the math problems. Massed practice in references to studying is typically referred to as “cramming,” where individuals study intensively to absorb mass amounts of volumes of information in a short period of time.8 The study found that students using spaced studying practices showed significant improvements over massed studying practices when tested a week into the study.

In the second part of the experiment, the math practice problems were grouped by either type or mixed randomly. Students who had solved and studied using randomly mixed problems were significantly superior to students who had solved and practiced problems that were organized by type. Researchers attributed these results to the fact that students who practiced with type organized questions, knew the formula for solving equations in practice, but not necessarily when to apply the formula when questions were mixed. By mixing these problems across several chapters in textbooks, students would both learn the formula and when to appropriately use each formula. Similarly, courses that have cumulative final exams are believed to promote long-term retention, as it forces spaced-learning to occur throughout the semester.8

Another example of spaced learning in education can be seen in a study by Bahrick in 1993. In a nine-year-long study, four different English-speaking subjects were asked to learn 300 words in a foreign language. Participants were given several training sessions conducted in spaced-out intervals over several days and then tested for their retention. The study found that having thirteen training sessions spaced across 56 days was equivalent to having 26 training sessions across 14 days, demonstrating the result of spaced learning, and the potential benefits if implemented in more mainstream learning practices.3

Example 2 - Advertising

The spacing effect has many applications in the business world, specifically in regards to marketing and advertising. For example, the spacing effect indicates that for a customer to remember an advertisement better, it would be recommended for the advertisement to be spaced out and not play the same commercial back-to-back on the television, or in other forms of media.

Researchers have concluded the assumption that spaced out ads are remembered better than ads repeated back to back.12 Additionally, advertisements with layout variation have an impact on converted sales. When studying website advertisements, researchers found that sales diminished if customers consistently visited the same website and were exposed to the same ad several times. In turn, if more time elapsed between website visits, the same presented advertisement had a more substantial effect on sales and positive conversions on the website.11

Summary

What it is

The spacing effect aids individuals in better remember and learning information. The spacing effect occurs when an individual repeats information over a spaced-out time, resulting in better recalling and retaining the information. 

Why it happens

The spacing effect is theorized to occur for a multitude of reasons. Popular speculated reasons for the spacing effect include concepts like how memories are encoded when we retrieve them, how repetition aids in remembering, and finally, the effects of Semantic Priming on recalling information. 

Example 1 – Studying

The spacing effect is commonly seen in cases of education and learning. In 2006, Dr.Rohrer created a two-part study where sets of students were taught how to solve different sets of math problems. Those who used the spacing effect to study completed the math equations and performed significantly better than students who used the massed study techniques.

Example 2 – Advertising

Examples of the spacing effect are also notable in marketing and advertising. Companies can better create memorable ads and products, by airing advertisements that are spaced apart over a more extended period of time, instead of ads that are seen or aired back to back. Ads that utilize the spacing effect to their advantage remembered better than their counterparts.

How to activate it

We can incorporate the spacing effect in our day to day, to promote better learning and decision-making abilities. The spacing effect can be activated by: scheduling spaced-out review periods, storing and organizing information by using applications such as Anki, SuperMemo or handmade flashcards, tracking progress, and reviewing in 30-minute intervals with breaks. 

Sources

Vlach, H. A., & Sandhofer, C. M. (2012). Distributing Learning Over Time: The Spacing Effect in Children’s Acquisition and Generalization of Science Concepts. Child Development, 83(4), 1137-1144. doi:10.1111/j.1467-8624.2012.01781.

About the Authors

Dan Pilat's portrait

Dan Pilat

Dan is a Co-Founder and Managing Director at The Decision Lab. He is a bestselling author of Intention - a book he wrote with Wiley on the mindful application of behavioral science in organizations. Dan has a background in organizational decision making, with a BComm in Decision & Information Systems from McGill University. He has worked on enterprise-level behavioral architecture at TD Securities and BMO Capital Markets, where he advised management on the implementation of systems processing billions of dollars per week. Driven by an appetite for the latest in technology, Dan created a course on business intelligence and lectured at McGill University, and has applied behavioral science to topics such as augmented and virtual reality.

Sekoul Krastev's portrait

Dr. Sekoul Krastev

Sekoul is a Co-Founder and Managing Director at The Decision Lab. He is a bestselling author of Intention - a book he wrote with Wiley on the mindful application of behavioral science in organizations. A decision scientist with a PhD in Decision Neuroscience from McGill University, Sekoul's work has been featured in peer-reviewed journals and has been presented at conferences around the world. Sekoul previously advised management on innovation and engagement strategy at The Boston Consulting Group as well as on online media strategy at Google. He has a deep interest in the applications of behavioral science to new technology and has published on these topics in places such as the Huffington Post and Strategy & Business.

Notes illustration

Eager to learn about how behavioral science can help your organization?