By Leo Babauta

As we evolve our learning practice this month, I’d like to introduce two ideas that are really the same thing but viewed from different angles:

  1. Interleaving & variety — instead of studying one topic to mastery and then moving on to the next topic, you mix topics together to make your learning more challenging and more effective and durable. The idea of “variety” is the same thing — basically, you vary your practice so that you’re not doing the same thing over and over. Instead of practicing a the same guitar chord, you try a few different chords. Instead of practicing the same basketball jump shot over and over, you take a variety of shots from different places on the court.
  2. Desirable difficulty — this is the idea that it’s good to make your studies a bit more challenging, because it makes learning more durable and meaningful. If the learning comes easy, it doesn’t last very long.

Let’s talk about why these ideas are important, and then how you might use them in your learning sessions.

Interleaving & Variety

Studies have shown that “mass study” — where you might study the same thing over and over again until you master it, and then move on to the next topic — doesn’t work as well as mixing things up.

That goes against our intuition. Most of us feel like we’re making more progress when we study the same thing repeatedly. But this feeling of progress is an illusion, it turns out — when students mix up topics, they learn better.

The first reason this is true is that when we study the same thing, our minds already know what we’re studying. But that means you’re already primed for that kind of problem, so it’s easier. For example, if you study multiplying things by 5, then it’s much easier to answer the questions. But what if you added in some division and multiplying by other numbers, and some exponents as well? You’d have to figure out what kind of problem you’re solving each time, and that is a more difficult but very good skill to learn.

The next reason is that making things more difficult, as we’ll see in the next section, is almost always better. Interleaving topics (mixing up the topics in one study session) makes the study more difficult, which means it’ll stick with us longer.

Variety is kinda the same thing — imagine trying to get better at hitting a baseball, and swinging only at fastballs over and over. After doing that for a week, you start practicing hitting curveballs. You’ll feel like you’re mastering each one, but studies have shown that you’ll actually be better at hitting if you mixed up the fastballs and curveballs from the start.

Varying your practice feels more frustrating, and it feels like you’re not learning. But in fact, you’re learning better, because in the real world, you don’t know what kind of pitch you’re going to get. You have to adjust instantly when you play a real game. So developing this kind of instant assessment and adjustment is important, not only in all sports but in academic subjects and other skills.

Desirable Difficulty

One of the reasons interleaving and variety work so well is that they make things more difficult. And difficulty is desirable in learning.

Not all difficulty is desirable — if it’s too hard, you’ll just fail repeatedly and eventually give up. The difficulty has to be appropriate to your level, and it’s important not only to fail but to succeed as well.

That said, when you only succeed, it’s too easy. You’re not learning anything new. And difficult learning lasts longer, studies have shown over and over. Making text less legible, for example, makes you remember it better. Testing yourself to recall the information is more difficult than just reading or watching it, but it’s more effective. Playing opponents who are better than you, and who will usually beat you, is more difficult than playing opponents who you’ll beat every time, but it creates rapid improvement.

Incorporating These Ideas into Practice

Basically, we want to get away from anything that’s too easy, and we don’t want to do mass study — studying the same things over and over until we feel we’ve mastered them.

Mix things up, and give yourself more of a challenge.

Some examples:

  1. When you learn new topics, introduce new topics before you’ve mastered the last one.
  2. When you test yourself, test yourself in a variety of topics, not just the same one.
  3. When you practice a skill, practice it in varying ways, so that you must adjust as you do it.
  4. Allow yourself to feel that you’re not making progress, and don’t listen to this feeling. It’s false.
  5. Always challenge yourself to something more difficult, even if that means a bit of frustration. You should have some successes, but lots of failures too. Learn from the failures.