Studying: Tackling the forgetting curve

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Studying: Tackling the forgetting curve

In this article, I’m going to talk about learning in general, and some methods for studying that I’ve been using.

For those that don’t know, (writing this in 2021) I’m a BSc Computer Science undergraduate student, and I’ve been attempting to achieve some certifications and study new languages, so managing my time is very important. Along my years in the university, I’ve been following some study methods, and I want to make a compilation of some of those, in order to hopefully help someone.

Learning

Learning simply means to gain knowledge. Specifically, it means ‘to gain knowledge towards an end’. To learn means to parse information and categorize them; analyze and come to conclusions. For many reasons, in our complex (‘civilized’) societies, we are forced to learn many things. Be it job tasks, learning the subject of an upcoming test, or learning a new language, we need to consciously make an effort towards learning it.

At the core, learning is a process that results in a change in knowledge or behavior as a result of experience. Understanding what it takes to get that knowledge in and out (or promote a behavioral change of a specific kind) can help optimize learning.

Of course, learning isn’t a one-size-fits-all scenario. Certain subjects have an intrinsic difficulty higher than others (although you can soften that by having a better memory representation using mnemonic techniques), and some people have an easier time learning than others, but that doesn’t mean that with sufficient effort, you can’t learn something.

Anyways, there’s the fact that learning can be a tricky thing: we read, we memorize and we practice, and still, the information doesn’t always stick. Basically, learning requires learners’ motivation and cognitive engagement to be sustained when learning complex ideas, because considerable mental effort and persistence are necessary.

With that in mind, I want to share some possibly useful tips for learning and studying in general.

Forgetting curve

First off, why is it important to study effectively? Simply put, it’s because our brains are “designed to forget”. If you don’t put enough effort into learning, or do it ineffectively, you will end up wasting time, and forgetting everything you’ve just learned.

The forgetting curve is a hypothesis that supports one of the seven kinds of memory failures: transience, which is the process of forgetting that occurs with the passage of time, hypothesizing about the decline of memory retention in time. This means that, if there’s no attempt to retain information, it is lost.

However, some memories remain free from the detrimental effects of interference and do not necessarily follow the typical forgetting curve as various noise and outside factors influence what information would be remembered.

A typical graph of the forgetting curve purports to show 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. Below, I’ll be including Hermann Ebbinghaus’ graph for the forgetting curve, showing the retention percentage by the elapsed time since learning.

Image: Ebbinghaus' forgetting curve

Why is this important? Well, for many reasons. Understanding how you forget, makes you understand how to study. First off, you need to understand your motivations. Is your objective just passing a test? Well, you can pull an all-nighter and cram to pass the test. Will you remember what you have studied one day after the test? Probably not.

If your objective is to retain information for a long period of time (e.g. learning a language), forgetting is undesirable. The problem with forgetting is that, although you can re-learn things, time is a precious asset and you don’t want to waste it when you don’t need it.

Of course, even with the retention rate being high, there’s always the possibility that we end up forgetting something, by some kind of brain fart. That is natural and may be increased by some factors such as aging, sleep deprivation, anxiety, and alcohol.

Tackling the forgetting curve

So is it all doomed? Since we are fated to forget, what can we do? Well, that depends. Of course, if you review things every day, hour, or even minute, it’s granted that you won’t forget what you’re trying to learn. But do you really have the time to review everything you have ever studied in your life every day? Unless you are in elementary school, I’d guess you don’t.

Reviewing efficiently is the key to save time and effort while trying to learn something. The forgetting curve has an intresting propriety: the longer you maintain knowledge, the easier it gets to continue maintaining it. That means that the longer you maintain information in your brain, the probability that you won’t forget it raises. Hermann Ebbinghaus’ premise was that each repetition in learning increases the optimum interval before the next repetition is needed (for near-perfect retention, initial repetitions may need to be made within days, but later they can be made after years).

A clear example of that is your native language. Do you really have to make any effort to remember common words (that you’ve been using/remembering frequently throughout your life)? Or even some uncommon words, if you force yourself to learn them, and it gets refreshed every once in a while (e.g. you see it in an article or newspaper), you’ll probably remember it even years after the last time you saw them.

For that reason, the optimal time to review something, and not waste any time, would be before the forgetting curve’s retention ratio gets too low, that is, right before we forget something. The graph below illustrates the forgetting curve when reviews are added.

Image: Forgetting curve with reviews

That being said, although we can’t “remember when we forget”, it’s possible to have some educated guesses about the estimated time. Multiple models have been created in order to assist a student in the process of learning, and we’ll be discussing some of them.

Spaced repetition

Spaced repetition is an evidence-based learning technique proposed by Hermann Ebbinghaus, that is usually performed with flashcards. Newly introduced and more difficult flashcards are shown more frequently, while older and less difficult flashcards are shown less frequently in order to exploit the psychological spacing effect. The use of spaced repetition has been proven to increase the rate of learning.

Spaced repetition is commonly applied in contexts in which a learner must acquire many items and retain them indefinitely in memory. That is perfect for the long-term learning scenario, and spaced repetition tackles perfectly the repetition need in the forgetting curve we discussed previously.

The notion that spaced repetition could be used for improving learning was first proposed in the book Psychology of Study by Prof. C. A. Mace in 1932: “Perhaps the most important discoveries are those which relate to the appropriate distribution of the periods of study…Acts of revision should be spaced in gradually increasing intervals, roughly intervals of one day, two days, four days, eight days, and so on.”

Gold List Method

The Gold List Method is a method that uses Spaced Repetition to learn vocabulary for languages. It was invented by David James. It follows very precisely the Ebbinghaus forgetting curve which takes into account your short-term memory. Sometimes the retention will be higher, sometimes it will be lower depending on your choice of words.

The explanation of the method can be found in the video below:

Basically, The Goldlist Method is just a spaced repetition method with bigger intervals. That makes it less effective than most spaced repetition programs right off the bat. A suggestion for improvement would be to start building sentences with the words for every distillation.

SuperMemo

SuperMemo (from “Super Memory”) is a learning method and software package developed by SuperMemo World and SuperMemo R&D with Piotr Woźniak in Poland from 1985 to the present. It is based on research into long-term memory, and is a practical application of the spaced repetition learning method that has been proposed for efficient instruction.

Different algorithms have been used; SM–0 refers to the original (non-computer-based) algorithm, while SM-2 refers to the original computer-based algorithm released in 1987 (used in SuperMemo versions 1.0 through 3.0, referred to as SM-2 because SuperMemo version 2 was the most popular of these). Subsequent versions of the software have further optimized the algorithm.

Leitner System

The Leitner system (or the physical flashcard method) is a widely used method of efficiently using flashcards that was proposed by the German science journalist Sebastian Leitner in the 1970s. It is a simple implementation of the principle of spaced repetition, where cards are reviewed at increasing intervals.

In this method, flashcards are sorted into groups according to how well the learner knows each one in the Leitner’s learning box. The learners try to recall the solution written on a flashcard. If they succeed, they send the card to the next group. If they fail, they send it back to the first group. Each succeeding group has a longer period of time before the learner is required to revisit the cards.

Ideas similar to these have been implemented into a number of computer-assisted language learning and flashcard software. Much of this software makes use of so-called “electronic flashcards”.

SRS

Without a computer program, the learner has to schedule physical flashcards; this is time-intensive and limits users to simple algorithms like the Leitner system.

With the increase in access to personal computers in the 1980s, spaced repetition began to be implemented with computer-assisted language learning software-based solutions, enabling automated scheduling and statistic gathering, scaling to thousands of cards scheduled individually. To enable the user to reach a target level of achievement (e.g. 90% of all material correctly recalled at any given time point), the software adjusts the repetition spacing interval. Material that is hard appears more often and material that is easy less often, with difficulty defined according to the ease with which the user is able to produce a correct response.

Most spaced repetition software (SRS) is modeled after the manual style of learning with physical flashcards: items to memorize are entered into the program as question-answer pairs. When a pair is due to be reviewed, the question is displayed on the screen, and the user must attempt to answer. After answering, the user manually reveals the answer and then tells the program (subjectively) how difficult answering was. The program schedules pairs based on spaced repetition algorithms (using re-implementations of SuperMemo algorithms or algorithms that emulate the Leitner system).

One of the most well-known SRS is Anki, a free and open-source flashcard program using spaced repetition. The SM2 algorithm, created for SuperMemo in the late 1980s, forms the basis of the spaced repetition methods employed in the program. Anki’s implementation of the algorithm has been modified to allow priorities on cards and to show flashcards in order of their urgency. The cards are presented using HTML and may include text, images, sounds, videos, and LaTeX equations.

But studying is too boring!

Well, studying is not always the most interesting task within your day, but it is a necessary one. When you are required to sit through multiple hours of studying in a single day, it’ll surely be difficult to maintain your concentration, even more if it’s a subject you don’t like.

In 2020, I have studied kanji using RTK1 and Anki, learning 60 kanjis a day, and reviewing around 500 kanjis a day around the end of the list. Granted that I studied every day (including weekends and holidays), it took me a lot of mental effort to get through it, and a couple of hours daily that I had to dedicate to that task. Although there isn’t a cake recipe for this, some methods can help you get through studying with less mental burden, and possibly avoid getting on burnout.

Well, firstly, one of the most difficult parts of studying is to acquire the energy to go and do it. The activation energy is the amount of energy needed to start conducting a given activity, and this activation energy can be hard to get, even more when you don’t feel motivated.

Although it is considering being lazy, I think that this is kind of a natural stimulus used by your brain to save energy. Just staying on your cellphone browsing social media releases much more dopamine than studying, so you naturally don’t feel any motivation to get up and study.

Dopamine is a chemical produced by our brains that plays a starring role in motivating behavior. It gets released when we take a bite of delicious food, after we exercise, and, importantly, when we have successful social interactions. In an evolutionary context, it rewards us for beneficial behaviors and motivates us to repeat them. Although passing a test or achieving a goal can make you release dopamine, it’s way more difficult to obtain than just checking your smartphone’s notifications.

This is one of the reasons that I always recommend dedication and diligence rather than motivation. Motivation can come in bursts, and even if you really like something, in the first difficulty spike that the subject has, your motivation may drop, and you may quit the task. Building a studying schedule has many benefits, and if you build the habit of studying, be it 10 minutes a day, in a week you’ll have studied more than an hour, and that’s better than not studying at all.

The one-minute rule

But well, of course doing it isn’t as easy as just saying, but make it so that it’s manageable. It’s important to build small goals every day so that we don’t ever drop out of a task because of laziness.

The one-minute rule is one of those methods which will help you fight laziness and keep your purposes alive instead of letting them die of starvation. It says we must introduce changes into our lives within periods of only a minute. If you are able to maintain one minute of doing some task, continue, the hardest part is already over, beginning.

Trying to write something? Get up and write a phrase. Trying to read a book? Get up and read a paragraph. Trying to review an Anki deck? Get up and review a single card. After you take the first step, everything is much easier.

If, after taking the first step towards the thing you are trying to do, you don’t feel motivated to continue, try again later. You already did something, so, even if you spend the rest of the day without motivation to continue, at least the day didn’t pass by without any progress.

Pomodoro technique

The Pomodoro Technique is a time management method developed by Francesco Cirillo in the late 1980s. He wrote, “I discovered that you could learn how to improve your effectiveness and be better able to estimate how long a task will take to complete by recording how you utilize your time.”

The Pomodoro Technique is useful if you get distracted while working on a project or want to understand how long a task takes. It’s ideal for many types of work including writing, coding, design, and studying. The technique also works if you have a lot of repetitive work to get through, such as wading through a busy inbox.

The technique uses a timer to break down work into intervals, traditionally 25 minutes in length, separated by short breaks. Each interval is known as a pomodoro, from the Italian word for ‘tomato’, after the tomato-shaped kitchen timer that Cirillo used as a university student. There’s an awesome video that shows the steps to use the pomodoro technique.

The important part here is the regular breaks. Four pomodoros form a set. A longer (15–30 minute) rest is taken between sets. This not only aids assimilation, but makes it so that you have some mental rest, and you can get back more motivated after the break. You are much more likely to maintain concentration, since you aren’t cramming for long periods of time in a row, and you’ll have time to manage all possible external stimuli during your break times.

Specific cases should be handled with common sense: If you finish a task while the Pomodoro is still ticking, the following rule applies: If a Pomodoro begins, it has to ring. It’s a good idea to take advantage of the opportunity for overlearning (practicing newly acquired skills beyond the point of initial mastery), using the remaining portion of the Pomodoro to review or repeat what you’ve done, make small improvements, and note what you’ve learned until the Pomodoro rings. It’s also important to note that, during your breaks, take the break. Stop what you are doing and give yourself some time to recover.

Final thoughts

While this has helped me immensely through my student journey, don’t take this for granted, and take everything with a grain of salt. There’s so much that I haven’t talked about, and I recommend you to search other sources and make improvements to the methods that I’ve talked about.

Anyways, I hope that something here can aid you through your learning journey, and feel free to contact me if you have any suggestions, criticisms, or contributions.

References and resources