What is the Ebbinghaus forgetting curve?

The spaced repetition methodology has roots that date back to ancient times. However, arguably the key influencer of the modern interpretation of it is Hermann Ebbinghaus, a German psychologist who pioneered investigations into memory. He is best known for his 1885 publication which would later became known as Memory: A Contribution to Experimental Psychology which first described the Ebbinghaus forgetting curve.

What is the Ebbinghaus forgetting curve

The Ebbinghaus forgetting curve is an exponential relationship between memory retention and time. When plotted on a graph it shows that the retention of new knowledge will halve in a matter of days or weeks if no effort is made to embed it. More importantly, it shows that if a conscious effort is made to retain the knowledge, by revisiting it periodically, the likelihood of it embedding in long-term memory is dramatically improved. The proactive practice of such revision would become known as spaced repetition.

What does the Ebbinghaus forgetting curve look like?

The Ebbinghaus forgetting curve is based upon the observations that the sharpest decline in retention occurs within the first twenty minutes and is significant within the first hour. The curve then levels off after a day. An important principal behind it is that increasingly-less information is retained after each attempt of revising – a key principle to why cramming for exams is inefficient.

His methodology is described in thus, “Ebbinghaus would memorize a list of items until perfect recall and then would not access the list until he could no longer recall any of its items. He then would relearn the list and compare the new learning curve to the learning curve of his previous memorization of the list. The second list was generally memorized faster.”

When plotted on a graph it looks like this…

Ebbinghaus forgetting curve
forgetting-curve-wozniak spaced repetition schedule
source: Gwern

The periodic repeating of learning would become known as spaced repetition (also known as distributed practice) and, in recent times, has been enhanced to create an optimised spaced repetition schedule. The addition of computer software to the schedule has meant that this methodology has become even more effective because the computer remembers which answers you got right and so doesn’t waste time and effort repeating related questions.

The Ebbinghaus forgetting curve and spaced repetition are now core principals in the learning toolbox and, in recent times, are being increasingly embraced in institutional and corporate training alike.

If you’d like to know more about EdApp’s spaced repetition implementation (called Brain Boost) within its training App, get in touch at enquiries@edapp.com. You can also try EdApp’s Mobile LMS for free by signing up here or in the box below.

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