Understanding the Ebbinghaus Forgetting Curve

By: Andrew A. DeMuth Jr.

Understand the Ebbinghaus Forgetting Curve in law enforcement training.
This article was originally published in the Spring 2026 edition of the ILEETA Journal.

 

You just wrapped up a two-hour block on tactics during motor vehicle stops. The class went well, and you are going through the evaluations: 9, 10, 10, 8, 10.

Great numbers. The comments are just as positive. It’s too bad that within one month, they will have forgotten almost 80% of what you taught them.

This isn’t because the instructor failed, the students weren’t motivated, or the material wasn’t important. It happens because the human brain forgets predictably and rapidly, unless training is designed around how people actually learn. This phenomenon of eroding retention is nothing new; it has been around since the 19th century and is known as the Ebbinghaus Forgetting Curve.

Unfortunately, concepts like the Ebbinghaus Forgetting Curve are not taught in most entry-level instructor development programs. In fact, much of this initial training focuses far more on public speaking than on instructional design. In New Jersey, like most states, law enforcement professionals interested in teaching at local academies must take a state-required course titled Methods of Instruction or MOI. It is a fantastic program consisting of six intensive days on presenting. While it does include important topics such as learning objectives and lesson plans, the primary emphasis remains on delivery rather than retention.

Herman Ebbinghaus was a German psychologist whose work dates to the late 1800s. He was a pioneer in the field of learning and retention. To eliminate prior knowledge from his research, he created over 2,300 nonsense syllables such as dax, bok, and yat.

After memorizing these syllables, Ebbinghaus tested himself at various time intervals. The results were eye-opening:

  • After one hour, he had forgotten approximately 56%
  • After one day, he had forgotten about 67%
  • After one month, he had forgotten nearly 79% (Murre & Dros, 2015)

In other words, one month after attending one of your training sessions, it is possible that your students only retain roughly 20% of what they learned. Again, eye opening.

At the 2026 International Law Enforcement Educators and Trainers Association (ILEETA) Conference, we will be breaking down the Ebbinghaus Forgetting Curve in our presentation, 11 Training Concepts Every Law Enforcement Trainer Needs to Know. This session examines a number of foundational learning principles that directly impact how well training is retained and applied in the field. The focus is on practical, trainer-relevant concepts that help move instruction beyond good presentations and toward lasting learning.

In the opening of this article, I intentionally described the retention loss as the worst-case scenario to prove a point, but there are steps that both trainers and motivated learners can take to mitigate the effects of Ebbinghaus.

The most effective mitigation technique is spaced repetition. This involves reviewing the material after the training at spaced intervals: several hours, 24 hours, 7 days, 30 days, and beyond. Even brief reviews lasting only a few minutes can significantly flatten the curve. This is also one of the strongest arguments for law enforcement to embrace microtraining, a highly effective method that delivers focused 5 to 10-minute training blocks that reinforce previous training or provide concise overviews of key topics.

Another powerful strategy we will be covering, which is also an excellent technique to reduce retention loss, combines two instructional concepts: priming and boosting. Priming prepares the brain to receive new information and can even introduce some of the concepts before the training even begins. Boosting reinforces the material after the initial training.

For example, when preparing for a class on vehicular pursuits, instead of just posting a generic class announcement, consider using a title with bullet points:

  • Why only two police vehicles may engage in a pursuit unless otherwise authorized by a supervisor
  • Why police may never pursue a vehicle while transporting a civilian
  • When police motorcycles must disengage from a pursuit

You might send another primer disguised as a class reminder with a few more important bullet points two weeks out and another a day out. When training begins, provide a short fact sheet at registration for them to review before the class gets started.  Then, begin the class with a diagnostic assessment. This not only gauges baseline knowledge but also reinforces learning and highlights gaps participants didn’t realize they had. This will often enhance attention during the class.

When executed properly, priming can start learning before the class begins.

After the class, boosting can take place in different forms:

  • Send a follow-up thank-you email that includes key takeaways
  • Post a few short question and answer bullets on your agency’s training bulletin board (training bulletin boards can be effective when frequently updated with relevant information).
  • Create a one-page fact sheet so sergeants and unit leaders can reinforce the material during roll call or at the beginning of specialty unit meetings.
  • Begin the next agency training with a five-minute boost of the previous training. If fact, make this a standard practice.

With limited budgets and competing demands, our training units need to derive the maximum benefit out of each and every training event.

Join us at the 2026 ILEETA Conference in St. Louis, MO, and take your training to the next level!

 

References

Murre, J. M. J., & Dros, J. (2015). Replication and analysis of Ebbinghaus’ forgetting curve. PLOS ONE, 10(7), e0120644. https://doi.org/10.1371/journal.pone.0120644

 

Andrew A. DeMuth Jr. is the founder of Leading Blue, a leadership development firm serving law enforcement agencies and private-sector organizations. He spent more than three decades in law enforcement with four agencies, serving in a wide range of leadership roles, including investigations commander, range master, agency training officer, public information officer, and director of a youth police academy program.

For more than a decade, he managed New Jersey’s CODIS DNA collection program, overseeing compliance, operations, and training for more than 500 participating law enforcement agencies and correctional facilities. He has also served as an adjunct professor at two institutions and speaks throughout the country on leadership, supervision, organizational culture, and professional development.

He is a passionate advocate for transforming law enforcement leadership development from a collection of isolated courses into a modern, comprehensive system that deliberately prepares leaders at every level to build stronger people, stronger teams, and stronger organizations. Visit our Leadership in Law Enforcement page for more articles on leadership.