Memory and the Spaced Repetition System

Principle

The human memory is very different from a computer memory. It works by association, and not by address. It is necessary to know two basic facts. They are rather counterintuitive, that's why many people complain they have a bad memory, while it seems perfectly operational for other persons.

- Forgetting is the main function of memory. Without forgetting meaningless information, which is incredibly plentyful, meaningful information would have no chance to be useful.

- Memory works in two equally important ways : storing and recalling. That is self explanatory, but the second one is often ignored.

Now memory is very hierarchized, or tiered. There is the working memory, the long term memory, and there are also two intermediary stages we'll call the short term and the medium term memory. They distinguish themselves in two aspects, obviously the life time of the information stored in it, but also the time needed to write in them, and inversely the capacity. The capacity of the human memory is virtually infinite. It is able to remember all and every perceptions in a whole life. Although that is tantalizing, it wouldn't be a good idea at all! (Actually, nothing is forgotten, it merely becomes unaccessible. It can be reached again through relearning or hypnosis.) That's much like the different types of memory in a computer : registers, cache, central memory and hard drive, but the information must be stored in one memory in order to pass to the next one. So it is understood that using efficently one's memory is more an issue of gestion than of brute force.

Why doesn't cramed repetition work? We have seen that the goal is to transfer the information to the next tier. By cramed repetition, it is stored in the short term memory, and any further repetition do nothing. Then it is rapidly forgotten, and there is no time enough to pass to the medium term memory. That's why spaced repetition is better, since the partially erased memory is refreshed, and remains a much longer time.

The rough caracteristic times of each type of memory are the following :
Working : 30 seconds
Short term : 7 days
Medium term : 7 weeks
Long term : > 1 year

Howto

The principle of the system then goes as the following :
First learn the item or a list of items. It is useless to spend more than a minute once it is in memory. One week later comes the time to practice recalling, so try and recall the stuff. If you can't, learn it again and do the same thing one week later, until you can. When this point is reached, the items are stored in medium term memory. Do the same process again, but this time with an interval of 7 weeks or so. This requires a good organisation. Flash cards get rapidly a mess when there is much to learn. Use instead properly named computer files or something like that. Lest you be overwhelmed very fast, begin slowly with few material each day.

There are applications for many platforms that implement a very similar system, and are much more handy. One of the most popular is anki

This method is literally a machine gun. As an illustration, I'll tell my own story.

As soon as when I am a five year old kid, I discovered a learning book of German, and set about studying it. It was my first passion. I could only remember a few words from the first pages, and didn't have any idea about what speaking a foreign language meant. In secondary school I naturally chose German, but the academic testing gave me a very harsh feedback, and I elicited the fury and the dispair of my teachers. My motivation got very faint. Even after high school and nine years of German study, my knowledge wasn't enough to have any practical use of the language. Some time later, I got further motivation and still insisted, with my old book, by listening to the radio, with other material, but the words couldn't stand in my memory, it was unhearting. I then began to read some text, newspapers and magazines mainly, and I underlined unknown words, the meaning of which I looked up in the dictionary, expecting to enlarge my vocabulary. I repeated the ones I saw the preceding days. This practice got more systematic over time, taking advantage of some advice on memory I read in a book from a famed pedagogist, until I arrived to the full-fledged space repetition system I explain here. For the first time, I got some words available in my memory, and I could read texts more fluently. Seven years later, I crossed off this task from my to-do list and at last closed the window, I was then thirty-five years old. In the momentum, I had learnt English and Spanish too. Yes, this text is from a French speaker who had awful difficulties with language learning. In the sequel, I've also learnt Italian, and the bases of Dutch.

You can trust when I say that this method works very well. Trying it is adopting it. This web page is about the history of the spaced repetition system, and explains why such an efficient method isn't used by the teachers.

Various tips

Learning a song or a poem

Ironically, one of the toughest challenge when learning such pieces of work is repetition of words. That's because they normally don't occur in them. The easy fix is to look for the repetitions, and to learn them first.

Rhymes are not there by chance, nor only to sound nicely, they were a terrific mnemotechnical tip at the time of oral traditions. Don't refrain from using them!

To memorize or repeat a verse or a section of any size, follow this procedure :
- Read a line, and say or sing it without looking.
- Do the same with the next line.
- Do the same with both lines.
- Do it all again for the next two lines.
- Do it again for the four lines.
- You got the idea, all but learn and recall while multiplying.

Learning a language

You won't learn a language in three months. You'll be fooled into thinking you master a language because you'll use the same unsignificant words of small talk, whose goal is to entertain social relationships but not to convey information. Even as a child, if you recall correctly, it took much more time to understand every words in a conversation between adults. It seems to have been painless because it was in the past. Anyway, the rule is, the more quickly you learn, the more quickly you forget. Learning a language is necessarily long, because it is a skill we use during all the day.

It may be tempting to focus on the grammatical structures and basic words, but it won't lead to a pratical use. To have a global understanding of any general text, the complete mastery of around 10.000 words is needed. That then allows to learn new words by practice through the context. That's where spaced repetition comes to play. Of course few words are used most of the time, and it is good idea to learn them first. So lists of words, even meaning related, is not the best way. Getting them in a text while reading for example is a better option.

The specific challenge of languages is similar words. They merge in memory and their meaning get blurred. So in case of unusual difficulty, check if a word differing in one letter or something is existing too.