Spaced Repetition. Let me say that again. Spaced Repetition.

If your goal is to check a box that says ‘training delivered,’ this blog isn’t for you. However, if you really want to change behavior or sharpen a skill, let’s talk about spaced repetition. 

Basically, spaced repetition is the opposite of cramming. Can’t say I remember anything I learned while cramming for finals in college. However, the skills and knowledge that I’ve learned through repetition have stuck with me. I still remember my boss’s redlined edits, pages crisscrossed with corrections to meet writing standards as a technical writer. Years later, those habits are second nature: click a button, select a checkbox. It has stuck with me because I learned it, practiced it, and repeated it. 

Spaced repetition strengthens learning by revisiting content over time, each time at a deeper level. This happens because of the forgetting curve. That training you spent tens of thousands of dollars on? A large portion is gone quickly, even within hours.

The chart below, based on Dr. Hermann Ebbinghaus’ studies and later replicated by Murre & Dros (2015), shows how quickly retention declines. After 20 minutes, only about 60% is retained. After a month, that number drops to around 20%. Spaced repetition matters because it interrupts and reshapes this curve.

Time	Approx. retained (%)
20 min	~60%
1 hour	~45%
9 hours	~35–40%
1 day	~30–35%
6 days	~25%
31 days	~20%

Spaced repetition works by boosting memory strength with each review and making forgetting slower over time, so each subsequent decline is less steep and lasts longer. Ideally, the first review would be the first day after the learning session; the second after 3 days; the third after a week, and the fourth 2-4 weeks later. Each interval gets longer because the memory is more stable.

There are various ways to implement spaced repetition. One of my favorites is pre-work and post-work after a learning session. The pre-work “primes the pump” for the learning session so the audience comes into the session with a basic understanding of the content. Learning during the session is more meaningful. Post-work can be used for participant output because producing something always helps to solidify the learning. Another favorite is the use of microlearning. In today’s fast-paced, ever changing corporate landscape, microlearning provides succinct, short learning that can be repeated with deeper learning in each iteration.

Spaced repetition isn’t always easy to implement, but if your goal is lasting behavior change, it’s not optional.