Spaced Repetition Featured in the New York Times


You’ve seen us write articles and publish white papers on the science of remembering for well over a year now. We are big believers in the spacing effect, and using what we know about the brain to enhance what people remember. Doing so has a measurable impact on employee retention from training, among other things.

It seems the New York Times has taken interest in spaced repetition as well. In a weekend editorial titled “How Tests Make Us Smarter,” Dr. Henry Roediger discusses how testing can be used as a valid tool to promote learning. Specifically, testing requires learners to retrieve knowledge from memory. According to Roediger, knowledge is solidified in our working memory when we practice retrieving and using it.

According to, Henry L. Roediger III is a professor of psychology at Washington University in St. Louis and a co-author of “Make It Stick: The Science of Successful Learning.”

Dr. Roediger goes on to mention how “many studies reveal that much of what we learn is quickly forgotten.” Therefore, “a central challenge to learning is finding a way to stem forgetting.” We could not agree more. Our research on the science of remembering (and forgetting) often comes back to the often-cited, and often misunderstood “Forgetting Curve.”

But testing alone does not provide the desired increase in retention. Here’s Roediger’s take. I’ve bolded some key points:

Retrieving knowledge from memory is more beneficial when practice sessions are spaced out so that some forgetting occurs before you try to retrieve again. The added effort required to recall the information makes learning stronger. It also helps when retrieval practice is mixed up — whether you’re practicing hitting different kinds of baseball pitches or solving different solid geometry problems in a random sequence, you are better able later to discriminate what kind of pitch or geometry problem you’re facing and find the correct solution.

While Dr. Roediger’s OpEd is specifically focused on testing students, the key points are applicable to corporate learning as well. In our Primer on Spaced Repetition and Feedback Loops, I connected the challenge of remembering  to the constant effort organization’s expend to deliver information employees need to know for their jobs. Rather than test scores, a great deal more is at stake. Organizations depend on their training to help employees have less accidents, make more sales, provide better customer service and make fewer mistakes.

Just like in the K-12 environment, the most common corporate learning methods are actually the least effective for learning when we take a look at the research. “Click next” eLearning courses, instructor-led sessions and PowerPoint slides are simply not enough to foster long term retention.

For this reason, we consistently integrate spaced repetition and feedback loops into both the custom learning solutions we develop and into the design of our Knowledge Guru game engine. We work with our customers to help them integrate Knowledge Guru games into a larger curriculum to maximize the retention benefits.

And while we carefully built spaced repetition into the design of Knowledge Guru, the research-based principles are available for anyone to take advantage of. As Roediger puts it, “As learners encounter increasingly complex ideas, a regimen of retrieval practice helps them to form more sophisticated mental structures that can be applied later in different circumstances.”

I encourage you to read the full article on Then, have a look at Dr. Karl Kapp’s take on spaced repetition or “retrieval practice.”