Spaced Repetition¶
Spaced Repetition is the systematic increasing of time between recalling a piece of information. Starting regularly and eventually waiting weeks or even months as the information becomes solidified in long-term memory.
Before we get into the "how" of Spaced Repetition, let's talk about what problem it solves.
The Forgetting Curve 
¶
When we learn a new piece of information, our brain can retain it for a small amount of time before it is forgotten. But each time we recall the information, it takes longer to forget. We have strengthened the neural pathway.
As an example, imagine your brain as a huge overgrown field. The grass is high and the smell of fresh air is strong. You identify some new information. In our example, imagine this as a box. You need to store the info (the box) somewhere in the field. So, with box in hand, you venture out into the field to find a suitable storage spot. As you walk, some of the grass is bent by your feet and a slight parting is made in the overgrown field. A faint pathway is created. You place the box down and walk back to where you started.
If you do nothing else, the grass will straighten, the infant pathway you made will disappear and there will be no visible evidence that you ever ventured into the field at all! The box will be lost — the information forgotten.
But being the clever sausage that you are, you recognise this. Just as the pathway is beginning to fade, you venture out to the box — you recall the information. This act, combined with the first, strengthens the pathway. It'll now take longer before the pathway disappears.
You repeat this process. Systematically venturing out to the box — recalling the information. Increasing the time between each trip. Until you have a dirt track. A clear pathway that is so easy to follow you can do it subconsciously. But there's a catch. If that dirt track is never walked again, it will eventually return to an overgrown field. It'll just take a long time.
Thus, we have the forgetting curve. Each time we recall a piece of information, we are strengthening the neural pathways in our brain and lengthening the time before those pathways are overgrown and the information forgotten.
Spaced Repetition¶
A wonderfully logical way to combat the forgetting curve is to practice Spaced Repetition. Once you have identified an idea or concept and created a chunk of information in your mind, capture that chunk in the form of a flashcard. Read the question. Once you've thought of an answer, turn over the flashcard and check if you're right.
Wait a few hours and then test yourself again. If you get the answer right, then wait until the following day and test yourself again. Continue this pattern of increasing the gap between each test until the knowledge is as rooted in your mind as you need it to be. But if you ever get it wrong, you have to reset and start by testing yourself the following day.
If you get an answer wrong, use it as a chance to re-evaluate. Why did you get it wrong? Was the gap between tests was too long for a successful recall? Do you need to grapple with the content further to increase your understanding? Maybe it's a dry topic and you need to find a creative way to remember the "boring" topic.
Automate With Anki¶
If you are someone who loves physical flashcards then you can ignore this section.
Anki is a fantastic spaced repetition tool that automates a lot of the timing decisions for you. All you do is create flashcards inside the app, and the app will take care of figuring out how long to wait before asking you the question again.
Make a habit of using Anki daily so that you benefit from the algorithm's timings. Try to hold off adding a new flashcard until you are sure the information is "chunked" in your mind. Little and often is the key to success. You have to be the tortoise in the race of knowledge, not the hare.
The internet is full of Anki-related resources so I won't go over the specifics of how to use the software. A quick Google search will lead you to countless blogs and the same goes for videos on YouTube. But be warned: Anki can be insanely simple if you want it to be, or insanely complicated. Keep it simple!
This content was inspired by A Mind for Numbers: How to Excel at Math and Science.