The Forgetting Curve

Dr. John Wittman

CSU Stanislaus

Hermann Ebbinghaus (1850-1909) was a German psychologist who founded the experimental

psychology of memory. Ebbinghaus’ research was groundbreaking at the time, and his work (though he

was not a proliferate writer) was generally well received. In recognition of his work in psychology, the

“forgetting curve”—the loss of learned information—is sometimes referred to as the “Ebbinghaus

Forgetting Curve.”

The graph on the left shows the

process by which forgetting occurs.

According to this research, people

tend to forget rather quickly after

learning material then forgetting

slowly levels out. The implications of

this for college students is obvious—a

day or two after attending class or

reading a chapter or article, students

will have forgotten approximately 75%

of what was learned. Moreover, most

of that forgetting happens within the

first hour.

However, although the forgetting

curve is a natural process, the process itself can be disrupted. That is, although it is natural for people to

forget much of what they have learned immediately following an experience, simple processes can be

used to slow down forgetting and to

help us retain much of the information

we will need to recall at a later date

(such as test time).

Take, for example, the chart on the

right. The green line shows the

hypothetical place where the forgetting

curve would start if we had the ability

to “remember everything after a

lecture.” The blue line shows where the

forgetting curve actually starts—

around 75%. Now take a look at the red

line. This line shows a dramatic

increase in memory if students review

material. Unfortunately, it also shows that without additional intervention one day after material is

learned content is lost, and one week after, recall is almost as if the review never happened at all.

So is there a way to maintain the initial recall after review? Yes, you simply have to keep at it. While an

initial review of material will help you

remember in the short term, reviewing

material multiple times and at

different intervals will help you retain

it for much longer.

The chart on the left shows how

review affects memory. You can see

that every time you review material

you both retain much more

information, and your forgetting curve

steadies out at a much higher level.

Each time you review material you

take much more away. Research

indicates that the minimum amount of

review is three.

Advice on Review

Much of college life is about being accountable for the ideas you learn as a student. In order to be

accountable, you have to be able to retain and recall information when you need it. Sometimes that

recall will be for tests, sometimes for conducting research, and other times for writing. Whether you

need to recall information from a lecture, from a textbook you read for class, or from research you have

done on your own, most students find it much easier to recall information when they have reviewed

material systematically. Below is advice about how to review.

 The first thing you have to do is to take well-crafted notes on material—this includes anything

you want to remember well such as a lecture, a chapter from a textbook, an article from the

library, etc. Without something to review from, reviewing would be impossible (taking notes will

be covered in another assignment).

 Right after class has ended or you have finished reading something, make a plan to review the

material. Remember, don’t wait too long before your first review. Try to review within at least

an hour. It’s good to take the opportunity on your first review to organize notes. You can

synthesize or expand ideas as you see fit or type your notes in something like Google Docs so

you have easy access to them—whatever you think will make it easier for you to keep at it.

 One week later, review again and test yourself on your recall. This will tell you how effective

your review is.

 A few weeks to a month later, review and test yourself again.

Reviewing information three times should give you a good start at overcoming the Forgetting Curve. As

you mature as a college student, you may find that other methods work a little better for you, so you

are encouraged to experiment. And, finally, always keep in mind that recall isn’t just about doing well on

tests. Much of the information you learn in college will be useful to you for years to come.