Example

An example makes it clear how spaced repetition works:

• You learn the word for the first time. Make sure that you learn it well enough to still remember it the next day.
• After one day you test yourself on the word. If you get it right, you will now remember the word for a bit longer.
• Two days later you test yourself again. If you got it right then you already know the word quite well.
• After another three days you test yourself again.
• Six days later you test yourself again.
• Etc

As you can see the interval keeps getting longer. Eventually the interval becomes so long that you actually remember the word forever. If you leave shorter intervals between tests then the tests aren’t as effective and you spend more time studying than you need to. If you leave longer intervals than recommended then it is possible that you will forget the word again and have to start (almost) from the beginning again. Wozzol calculates the point at which you should be tested on a word again.

Side effect: fun learning

With perfectly spaced repetition you learn extremely efficiently. A welcome side effect of perfectly spaced repetition is that it makes learning fun. A simple test is therefore neither too easy, nor too difficult, but challenging. You get a feeling of satisfaction when you know most of the answers in a test, but do have to put some effort into remembering everything. You will notice that you learn quickly which also provides extra motivation. You are learning well if you get a maximum of 10% of your words wrong. However, it’s better to only get a couple of percent wrong and get through your test a bit quicker.

Learn frequently for a short while

In order to test yourself at all the right times it is important that you study frequently for a short while. If you do this, the tests will happen at the right time and you will remember everything. If you learn a list of words which you test yourself on once four days later, it is quite possible that you will have forgotten everything. You can learn it afresh but with the chance that you will have forgotten it again four days later. You need to study every day in order to benefit from the spaced repetition and remember what you have learned in the long-term.