Spaced Learning For Long-Term Retention
When I think back on my time in school and college, some of the most vivid memories are of cramming for exams through the night—running on pure adrenaline, fueled almost completely by anxiety. More than 20 years later, I still get nightmares about blanking out during an exam, and I’m pretty certain I’m not alone. After years of formal education where academics were the primary focus, how much did I retain? Let’s face it—very little. The only things we tend to retain from our formal education are things that we’ve been able to apply in some form during life and work: concepts that we’ve revisited in different forms repeatedly and have had a chance to apply in real-life situations.
This can be attributed, at least in part, to what Hermann Ebbinghaus described as the "forgetting curve", which talks about how we tend to forget newly acquired information as time passes. Though Ebbinghaus’ theory has been criticized for various reasons, multiple researchers have attributed the encoding of information into long-term memory to how often someone is exposed to that information. An excellent piece of related research is Benjamin Storm’s paper titled "The Benefit of Forgetting in Thinking and Remembering", in which he elaborates on the way our brains function, by stressing the fact that “the ability to retrieve and generate information that is wanted, relevant, and appropriate is made possible by the ability to inhibit, and thus forget, information that is unwanted, irrelevant, and inappropriate."
What Does This Mean For Learning Design?
One of the most effective ways to improve the way we learn is to “interrupt the process of forgetting” (Brown, et al., 2017), which means retrieving the information from memory multiple times at spaced intervals. In his book Designing mLearning, Clark N. Quinn elaborates on two different applications of spacing in learning design: spaced practice (allowing learners to apply the information in different scenarios at spaced intervals to cement concepts), and spaced testing (reactivating the information by presenting learners with tests that trigger recall at spaced intervals). Not only does taking these approaches make the memory for the information last longer, but it also makes subsequent retrieval of this information easier. One marked benefit of this is that as the information gets more readily retrievable from memory, the information can be applied to varied contexts and situations more easily.
According to Hintzman, Dempster, and Russo et al., there are three primary reasons why spacing of learning can be effective. Let’s look at them from a learning design perspective:
- Encoding variability—taking information and recording it in long-term memory
The encoding variability theory says that if the information is repeated multiple times at spaced intervals through a variety of modalities, there is a deeper encoding of this information, leading to long-term retention and a deeper understanding of the underlying concepts and relationships. - Proficient processing—leading to long-term memory success
Research has established that repetitions in close succession are relatively less efficient in achieving long-term memory encoding than repetitions that are spaced. This can be attributed to boredom, mental fatigue, or the familiarity trap that comes into play when you read the same information repeatedly in close succession. Spaced repetitions allow for some forgetting between interventions, creating more memory connections that make retrieval easier and more contextual over time. - Learning-strategy adaption—learning through retrieval failures
It is now believed that since the spacing of learning interventions allows for some amount of forgetting, learners are more likely to fail in the initial attempts at retrieval. This acts as an inducement for learners to process information more earnestly and elaborately.
Does This Mean That We Have Found The Magic Sauce?
In a nutshell—no! Spaced retrieval by itself is of no value unless there’s an effective learning strategy woven around it. It is, at best, an enabler for retention, not a stand-alone learning solution.
In today’s business environment, most organizations are looking to L&D to be result-driven and are insistent on seeing its impact in terms of RoI. This means the role of L&D has clearly shifted from "teaching" learners concepts to "enabling" them to perform in a competitive work environment. In my next article, I’ll try to delve into how spaced learning can be leveraged in different forms within various learning modalities and delivery methods to support better workplace learning outcomes.
References:
- Brown, Peter C., Henry L. Roediger III, and Mark A. McDaniel. 2017. Make It Stick: The Science of Successful Learning. Cambridge, MA.: Harvard University Press.
- Quinn, Clark N. 2011. Designing mLearning: Tapping into the Mobile Revolution for Organizational Performance. San Francisco: Pfeiffer.