Educators educating Educators

Sep 26

Forgetting Curve



People usually forget 90% of what they learn in class within 30 days. Also, the majority of forgetting occurs within the first few hours after class.

Hermann Ebbinghaus was a German psychologist who pioneered the experimental study of memory, and is known for his discovery of the forgetting curve and the spacing effect. He was also the first person to describe the learning curve. He is most famous for discovering the most depressing fact in education. People usually forget 90% of what they learn in class within 30 days. Also, the majority of forgetting occurs within the first few hours after class. This has been confirmed many times since.


Hermann Ebbinghaus

In 1885, he published his groundbreaking Über das Gedächtnis ("On Memory", later translated to English as Memory: A Contribution to Experimental Psychology) in which he described experiments he conducted on himself to describe the processes of learning and forgetting.

Ebbinghaus made several findings that are still relevant and supported to this day including the forgetting curve, the learning curve, and the massed-spaced effect.

Arguably his most famous finding is the forgetting curve, which illustrates the decline of memory retention over time. The forgetting curve describes the exponential curve that illustrates how quickly we tend to forget the information we have learned. The sharpest decline is in the first twenty minutes, then in the first hour, and then the curve evens off after about one day.

Forgetting curve

Forgetting curve

Forgetting curve with reminders


The forgetting curve graph shows that humans tend to halve their memory of newly learned knowledge in a matter of days or weeks unless they consciously review the learned material.

Ebbinghaus also described the learning curve that refers to how fast we learn information. The sharpest increase occurs after the first try, and gradually evens out. This means that less and less new information is retained after each repetition. Like the forgetting curve, the learning curve is also exponential.



Welcome back to another school year. I hope your summer was relaxing and invigorating and you are looking forward to the approaching school year and the opportunity to stimulate and challenge your students’ minds.

This summer I was able to study Sir Ken Robinson, a British author, speaker and international advisor on education to governments, non-profits, and education organizations

I, like many people, find his writings and Ted Talks not only witty and inspiring but also thought-provoking and challenging. Much of his work deals with the diversity of intelligence, the power of imagination and creativity, and the importance of commitment to our own capabilities. He posits that the noticeable lack of them in our schools negatively affect students’ learning and teachers’ productivity and the absence of them is triggered by the demands of standardized testing.

I hope you find Sir Ken Robinson’s words inspiriting and challenging as I do and be mindful of them as you plan for the new year. Here is to a great 2017-2018 school year!