The Ebbinghaus Forgetting Curve – And How To Overcome It

“I hear and I forget. I see and I remember. I do and I understand.”
– Confucius

If I gave you a list of nonsense 3 letter words right now, how long do you think you would remember them?

How long could you remember at least half of them?

In 1885, Hermann Ebbinghaus did this exact experiment – and his results are widely accepted as a general theory for how we learn and retain information. Graphing his results, he developed a formula for how long items remain in our memory. Some people may remember better than others, but the general trend for how long we retain information is the same.

The resulting graph is called Ebbinghaus’ Forgetting Curve. The bads news is, it’s steeper than you may think. The good news is, there are strategies you can use to improve your memory retention.

How Quickly Do We Forget?

According to Ebbinghaus, the level at which we retain information depends on a couple of things:

The strength of your memory
The amount of time that has passed since learning

The shape of the curve is defined by the following equation: (Warning: math ahead!) Retention = e ^ -(Time/Strength of Memory)

It’s easier to see in a graph:

Keep in mind, your unique memory strength will determine whether you retain half the information for 3 weeks (as in the graph above) or more, or less. Depending on what you’ve learned, especially classroom style, I’ve read estimates that say we forget 90% within the first month – or even first week!

How Can We Retain More?

There are two primary factors that affect our level of retention for items in our long term memory:

Repetition
Quality of memory representation (I’ll get to discussing what this is below)

Repetition is easy enough – the more frequently we repeat something, the more likely it is to stick. For this reason, one suggestion given to improve memory retention when taking a class is to review your notes and classwork regularly. Research has shown that reviewing at regular intervals does increase retention and that over time, less frequent review is needed.

Below is how the graph looks if you review what you learn once after two weeks, or twice – after 2 weeks, and then after a month:

The takeaway from the graph above is this: frequent review can help retention, but over time, we still tend to forget what we’ve learned. This is why reviewing and cramming for exams can provide dividends in the short term – only to lead to you forgetting everything you had quickly learned/memorized immediately after.

There is one caveat though: one aspect that can increase retention (and that is not accounted for in the graph above) is that vague phrase mentioned above – quality of memory representation. There’s also some debate about how much retention is affected based on how meaningful the information is.

So, how does this graph change with the quality of memory representation?

Quality of Memory Representation and Meaning

A better approach for long term retention is to focus on the quality of the information represented in memory and the meaning of the information to you. In plain English – the more relevant, meaningful connections you can make with the new information in your mind with things you already know, the better your memory retention over time. As this is much more difficult to graph, let me sum it up like this:

If you learn something, and it is important to you, and you can connect it with many things you already know, your memory retention will be very high
If you learn something, and it is not important to you, and you do not connect it with anything you already know, you will have poor retention and require regular repetition (as in the graph above)

So how can we create long term retention through more meaningful connections?

The short answer is that rather than trying to memorize everything (referred to as the rote method of learning), we need to relate what we learn and draw connections.

Drawing Connections With Holistic Learning

Scott Young knows far more than I do on the subject of learning, and in his writing contrasts rote learning with holistic learning. He describes it like this:

“Instead of trying to pound information into your brain with the hopes it will simply fall out when you need it, holistic learning is the process of weaving the knowledge you are learning into everything you already understand.”
– Scott Young, Learn More, Study Less

I researched holistic learning a bit as I was writing this, and Scott has put together what has got to be the most complete resource out there. He has a whole series of videos available discussing how to learn, but covers a variety of other topics as well – from speed reading to how to set goals you’ll actually achieve. One of my favorite videos was his discussion on flow based note taking – which I’ll discuss in the future.

For more information, check out Learn More, Study Less.

How Quickly Do We Forget?

How Can We Retain More?

Quality of Memory Representation and Meaning

Drawing Connections With Holistic Learning

Further Reading