I'm building an app to teach myself French, and I wanted to share what I learned in the process of creating it!

We are slowly entering an era of digital personalized learning, which will be much more efficient and much more fun than traditional classroom-based learning.

Creating a digital "learning system" is at least as hard as tutoring someone. Everything that you need to know to be a good tutor, you need to implement in code in your digital learning system. How to tell when the learner is stuck, what they need to review, and so on, all needs to be specified in advance rather than relying on your intuition. But digital systems has the advantage that it can scale to a potentially unlimited number of people, whereas you can only tutor one person at a time.

Because we spend so much of our lives learning, and because classroom-based learning is so much less effective than having a good tutor is, it follows that creating an digital learning system is extremely valuable, provided that people actually use it and that it gets close to the efficiency of having a tutor.

The foundation of effective learning systems is almost always a technique called "spaced repetition". This is partially because a computer can implement spaced repetition even better than a human can, and because it is extremely effective. Spaced repetition is not applicable to every field, but it is extremely relevant to language learning, so it deserves a quick introduction for those readers who are not familiar with it.

What is Spaced Repetition?

(If you already know what spaced repetition is, you can skip this section.)

Spaced repetition is a learning system normally used with flashcards. The naïve way of using flashcards is to review all of them every session. But as you start to have thousands of flashcards, this becomes a huge waste of time. No one can learn a lot of flashcards this way – your workload per day would be proportional to the number of cards.

A much more effective way would be to only review each flashcard right as you were about to forget it. The effect is that newly introduced and more difficult flashcards are shown more frequently, while older and less difficult flashcards are shown less frequently^[1]. This is accomplished using an algorithm called a "scheduler". You tell the scheduler each time you review a card, and you say whether you successfully remembered it or forgot it. The sch...

Akhil K Sugathan

Akhil K Sugathan