ATD Blog

Spaced Learning: An Approach to Minimize the Forgetting Curve

Tuesday, January 27, 2015

Effective long-term learning is rarely achieved by a one-off event, but designers all too often think of one-off events when building training solutions. However, as soon as the event ends, forgetting is likely to begin. It is an unfortunate fact, first spotted by Ebbinghaus in 1885, that we have not only a “learning curve” (where people take time to learn in the first place), but also a “forgetting curve” (where we lose what we learn if we don’t use it regularly). 

Effective learning strategies should therefore not only help people learn as quickly and efficiently as possible, but also minimize forgetting.  What can we do? 

Just-in-time performance support is one answer to this problem. If you learn something just before you need to use it, then there is no time to forget. However, most people can’t learn everything they need just before they need it; sometimes having to stop and look things up slows us down too much, or safety requires that we master and memorize information. 

Enter a Spaced Learning Approach

Clearly, we need another approach to complement just–in-time learning. Something that will help us learn and that will minimize what we forget. Spacing learning over time might just be that approach. 

There is a body of research that suggests that spacing learning over time helps people learn more quickly and remember better. It has been found to be effective in various domains, from sales training to language learning to medicine (Caple, 1997; Castel, Logan, Haber, & Viehman, 2012; Grote, 1995; Kerfoot et al., 2007; Lambert, 2009; Landauer & Ross, 1977; Lehmann-Willenbrock & Kauffeld, 2010; Toppino & Cohen, 2010). 

What does this mean in practice? 

If you are designing a learning program with spacing in mind, you will present learners with a concept or learning objective, allow a period of time to pass (days, weeks, or months) and then present the same concept again. This might involve a few repetitions, or many, depending on how complex the content is. 

Similarly, the intervals between repetitions might be adjusted depending on the content and the audience. Will Thalheimer’s research (see the list of links at the end of this blog) gives some useful pointers about the effect of using longer or shorter intervals. 

Repeating the concept might mean simply re-introducing that concept exactly as it was presented earlier or presenting it in a slightly different way. For example, concepts might be presented using a variety of different media, stories, and so forth. They might also involve delivery of a selection of similar but distinct practice exercises, or simulations delivered over time. 


Designers using the spaced approach need to settle on several different ways to present the same point, rather than thinking about the single best way, as we might for a more traditional e-learning course or face-to-face session. Designers also need to get even better at tightly defining learning objectives—as each one will need a lot of work and interpretation, there may be little room for ‘nice to have’ information!

When should you consider spaced learning? 

Sometimes a spaced approach will be appropriate as follow-up to a one-off event to minimize forgetting after that event. At other times, perhaps in conjunction with performance support, it may be possible to design an entire solution using this approach. Designing learning so that activities can be tackled in short bursts, spaced over time, may not only help learners remember over time but also reduce the need for large blocks of time away from the workplace to learn in the first place. It is likely to be particularly helpful for busy learners on the go, who can use mobile devices to access spaced learning in short bursts of ‘found time’.

It is worth noting that marketing campaigns have long known the importance of spacing repetition of key messages. They set out to create a ‘persuasive’ effect through a cultivation of familiarity which is achieved through repetition. Perhaps it is time for learning to take a lesson from marketing in spacing out material.

Additional Resources 



Caple, C. (1997). The effects of spaced practice and spaced review on recall and retention using computer-assisted instruction. Dissertation Abstracts International: Section B: The Sciences & Engineering, 57, 6603.


Castel, A. D., Logan, J. M., Haber, S., & Viehman, E. J. (2012). Metacognition and the spacing effect: the role of repetition, feedback, and instruction on judgments of learning for massed and spaced rehearsal. Metacognition and Learning. doi:10.1007/s11409-012-9090-3

Grote, M. (1995). The Effect of Massed Versus Spaced Practice on Retention and Problem-Solving in High School Physics. he Ohio Journal of Science, 95, 243–247. Retrieved from papers://3a07567f-5013-4eec-86cd-a5ef539fd065/Paper/p4355

Kerfoot, B. P., Baker, H. E., Koch, M. O., Connelly, D., Joseph, D. B., & Ritchey, M. L. (2007). Randomized, controlled trial of spaced education to urology residents in the United States and Canada. The Journal of Urology, 177, 1481–1487. doi:10.1016/j.juro.2006.11.074

Lambert, C. (2009). “Spaced education” improves learning. Harvard Magazine. Retrieved from

Landauer, T. K., & Ross, B. H. (1977). Can simple instructions to use spaced practice improve ability to remember a fact? An experimental test using telephone numbers. Bulletin of the Psychonomic Society, 10, 215–218.

Lehmann-Willenbrock, N., & Kauffeld, S. (2010). Sales training: effects of spaced practice on training transfer. Journal of European Industrial Training. doi:10.1108/03090591011010299

Toppino, T. C., & Cohen, M. S. (2010). Metacognitive control and spaced practice: clarifying what people do and why. Journal of Experimental Psychology. Learning, Memory, and Cognition, 36, 1480–1491. doi:10.1037/a0020949

About the Author

Imogen Casebourne is director of learning at LEO Learning. Imogen works with the learning design team to ensure that LEO's learning solutions remain cutting-edge and evidence-based. Imogen also plays a key role in LEO’s thought leadership program and undertakes research and consultancy for LEO’s clients, including the NHS, the ICS, and the Red Cross.  She is closely involved with LEO’s Civil Service Learning partnership, leading the team that worked on the bespoke content suite and later offering consultancy support to ongoing work on the portal.  Imogen speaks at conferences, including the 2014 mLearncon in San Diego, has published a report on mobile learning for the NHS in 2012, and conducted case study research focusing on mobile learning for the eLearning Guild in 2013. She is currently studying part-time for a Doctorate in Education at Oxford University with a focus on the use of mobile technology. Imogen has designed solutions for tablets and smartphones and led the team that won gold for “Best Use of Mobile Learning” at the E-Learning Awards in 2012.

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