Scientific study has proven that humans forget 50% of what they learn within one day of learning. After completing an online course, even the brightest minds cannot remember every piece of information presented.

We tend to forget information over time if we do not apply it to our daily activities. The Ebbinghaus Forgetting Curve commonly represents the effect.

Ebbinghaus Forgetting Curve

What is the Forgetting Curve (and How Do You Combat it)?
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In the 1880s, a German psychologist named Hermann Ebbinghaus tested his memory over various periods. He gathered all the data from his studies and plotted it on a graph similar to the one above.

This work gave birth to the Ebbinghaus Forgetting Curve, a mathematical formula that describes the rate at which memorized material is eventually forgotten. Ebbinghaus initially generated lists of random three-letter non-words (the fact that they were non-words was necessary; there was no pattern or hardcoding associated, which challenged the memory). Ebbinghaus then memorized these non-words until he could recall all of them correctly.

He then tested himself at intervals like half an hour or a day or a few days later to see how many of the non-words he remembered, which went as far as 31 days.

Ebbinghaus discovered that, over time, he would forget a significant number of these non-words. The rate and volume of forgetting over time were directly proportional to the passing time. So the forgetting process began as soon as he stopped referencing the list; it first progressed at a rapid pace, eventually tapping off over the week.

The forgetting curve is tricky to tackle, especially when remembering different formats of information shared in corporate training programs. Not all training information is engineered explicitly to battle this phenomenon. Thus, understanding the forgetting curve and its influences helps instructors create more effective training content while devising ways to aid in employee knowledge retention.

When we absorb content, we are actively making relational associations with other information that we already know. This knowledge or “cognitive economy” will come from our long-term memory rather than our short-term or working memory.

Implications of the Forgetting Curve

The general scientific consensus states that there are two primary types of memory.

  1. Working Memory – Helps remember simple information in the short-term. It is characterized by,
    • Limited Capacity – Learners can store only around 7 to 9 items at a time in their memory
    • Limited Duration – The information absorbed can be forgotten easily with time or due to distractions.
  2. Long-term Memory – Refers to information storage retrieved over an extended period. A repeated recall is vital to ensure that information retention persists through long-term memory because the information that is frequently accessed will become easier to recall over time. Any learning designer wants to ensure that their content resides in learners’ long-term memory, which is an essential mechanism to flattening the Forgetting Curve.

Typically, the higher the instruction’s cognitive load, the steeper the forgetting curve will be as learners struggle to build the schemas necessary for retention. Cognitive load is determined by the number of working memory resources a learner must use to ingest and retain information.

Reducing cognitive load is critical to designing effective instruction and can be accomplished in several ways. Chunking, retrieval practice, multiple delivery media, and spaced repetition are relatively straightforward methods that you can use to reduce cognitive load and flatten the forgetting curve for your learners. These techniques can be applied whether you’re building synchronous or asynchronous instructions and with or without self-paced elements.


Chunking refers to splitting or grouping complex, tangentially related information into cognitive chunks that form smaller, more cohesive groups. A three-day (21 seat-hour) instructor-led training course may comprise three basic groupings (one for each day) of loosely related information, but creating 10-12 chunks of highly associated information will help learner retention.

Another example of chunking is producing microlearning modules to reinforce the valuable information learned in training sessions. Each chunk of standalone learning content can last about 10 minutes, enabling learners to meet one learning objective at a time comprehensively.

Spaced Repetition

Spaced repetition reinforces learning at periodic intervals. Implementing spaced repetition must also include increasing the time between each repetition and increasing the complexity of the information presented. This way, the brain is trained for better recall. As time passes and the space between repetitions increases, the mind becomes better equipped to retain and recall concepts. Traditionally, using flashcards (there are myriad flashcard software packages), modern approaches also include using mixed-media and associated short quizzes pushed to the learner from a central learning function.
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Retrieval Practice

Implementing a technique that elementary-school teachers have been using for centuries in retrieval practice instead of only a review of a chunk of information, learners test their knowledge recall in a ‘free’ environment. A low-pressure environment where making mistakes does not lead to consequences allows the learner to take chances. Immediate feedback, with an explanation of the correct answer, is essential for recall and understanding.

Unlike spaced repetition, it does not require increased intervals and complexity. You can effectively implement the Retrieval Practice Method within a given training session or provide it through intersession activities. By merely testing knowledge, you are helping the learner to retain it.

Blending it up

Creating blended learning is another way you can help retention. By providing different avenues for acquiring related chunks of information, you provide individual learners the ability to find their own ‘a-ha moments.’ You’ll be looking at disseminating chunks through various media videos, podcasts, infographics, and myriad other possibilities at the basic level. However, as you progress along the blended continuum, you can achieve more effective knowledge transfer. Structuring an exercise to accomplish a task as part of software training can certainly be useful. However, a blended approach could involve assigning learners a group project to analyze the software usability related to a given set of tasks and present potential improvements.

Wrapping up

By making it easier for your learners to absorb and retain the content, you will more readily achieve the ultimate goal of all training, behavioral change. At Radiant, assisting clients with workforce transformation is one of our core missions; let us help you achieve your next learning initiative’s goals.