Lifelong learning is part of my operating thesis on what it means to be an intelligent, intentional human being. Most of the learning I do happens online, and I’ve done a lot of thinking about how to use technology in ways that make that process more efficient. 

In my system, there are three distinct phases:

  1. Discover relevant information.
  2. Collect the useful bits for later reference.
  3. Put the material into practical use. 

The first step is pretty straightforward. Most of us know how to use search engines and things like Reddit to help us discover information. I begin by going out and collecting information related to whatever I’m trying to learn. This normally comes in the form of articles, videos, podcasts, or books. 

As I make my way through the corpus of content that I’ve collected, I need a way to pull out the useful bits. This is the second phase of the process. 

I try to rely only on digital versions of books and articles so that I can use the built-in highlighting features of either Instapaper (for web content) or Kindle (for books). If what I’m after isn’t available digitally, I’ll either scan and OCR it (if it’s short form), or take notes in a digital tool as I read. 

Either way, my goal is to get a set of interesting digital artifacts as quickly as possible. 

It always surprises me how often people stop there. Once they’ve got their set of notes in Evernote (or Notion, or whatever), they’re done – time to move onto the next thing. 

That seems to me that they’ve created a system that is optimized for producing notes, not practical knowledge. 

The difference is that notes are inert. We can’t solve problems unless the material is available to us whenever we need it. 

The third phase of my system: “Put the material into practical use,” solves this problem, and it does so through spaced repetition. 

What is spaced repetition?

Spaced repetition is a method of study that helps us move things into long term memory. The general idea is that the best time to study something is just before you’re about to forget it. 

In the late 1800’s, a german psychologist named Hermann Ebbinghaus conducted a handful of experiments that established the forgetting curve. 

This curve helps us to understand when we’re likely to forget what we’ve learned. It also helps us to use our time efficiently, as we can focus each day on studying only the things that we need to, at this particular time. 

The other half of the method is active recall. If you’ve ever used flashcards before, you’ve engaged in active recall. Active recall means pulling something out of your brain. The inverse of this, like multiple choice, is passive recall. 

The magic is that each time that we engage in this active recall process, we strengthen the memory, which leads to long term viability. We want durable memories that survive over time. 

Said a different way, the active recall process solidifies our memories at the key times produced by the spaced repetition algorithm. 

…But I don’t need to study anything.

Oh, but you should. This stuff isn’t just for teenagers and med school students. I’d be half as effective at many of the things I care about today without spaced repetition. If I try to quantify the impact of spaced rep on my development career – I can’t overstate it. My most marketable skills are built on my spaced repetition system, full stop. 

It’s also somewhat likely that you’ve already used spaced repetition in some form or another. Many language learning programs are built on SR algorithms. 

I think that spaced repetition and active recall are criminally underreported on. I’m not the only one who thinks so… there was an article published in a psych journal several years ago, appropriately titled, “The spacing effect: A case study in the failure to apply the results of psychological research.”

How to get started with Spaced Repetition

As I mentioned before, I’m a big fan of digital media, primarily due to the portability of the content. I can take my highlights and export them into any format I’d like, for use in nearly any program I’d like.

So it makes sense, then, to choose an app for spaced repetition. That way we can simply copy/paste our artifacts into the system and go. 

There’s an open source piece of software called Anki. It’s available for Windows, macOS, Linux, Android, and iOS. All are free, excepting the iOS version.

Conveniently, Anki has a back-end sync service. My strategy consists of adding cards on desktop and then syncing them to my mobile device for study. I do my spaced repetition work every morning on my phone with a cup of coffee – it takes about 5 or 10 minutes, depending on the amount of new material I introduced the day before. 

Cards in Anki are analogous to flash cards. There are many different types of cards, but the one that I suggest you use is called a cloze deletion card

Cloze deletion is the process of hiding one or more words in a sentence. This is what it looks like: 

Cloze cards are better than regular flashcards because they can be a bit more dynamic. One sentence can be turned into two or more cloze cards that help create more durable knowledge.

It gets really interesting when you apply this concept to images through the image occlusion card type: 

I should mention that cards belong to decks. Decks are constructed according to a theme or topic. I have decks for things like grammar, programming languages, keyboard shortcuts, and US states (it’s a map with image occlusion to help me memorize every state visually). 

Decks are studied individually – so at some point, it makes sense to combine decks and get a random smattering of cards during each session. Otherwise, if we continue to see the same questions in the same order (unlikely, but possible) our brain will begin to contextualize and memorize the sequence and sentences (the representation of the information), and not the information itself. 

Dig in deeper 

I’m a big fan of spaced repetition and I’m beyond excited to share it with new people. I’m working on a video course that takes you through the entire thing, from soup to nuts. We’ll dig in deeper and understand the what, the how, and the why of spaced repetition. Along the way, we’ll also learn how to use Anki and review my personal system for knowledge management.  

01 - Introduction to Spaced Repetition

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Welcome to my course on Spaced Repetition. I’m Terry and I’ll be your host. 

This is a course about memory. Specifically, it’s a course that is going to teach you how to remember things with ease. Along the way you’ll also learn a little bit about how memory works,  my system for figuring out what is worth remembering, and how to use my favorite tool for actually putting the system into practice, called Anki. 

This course is for everyone. I’ve been deliberate about making the material approachable where I can. In my mind, this course should be viable for anyone high school age or older. 

First, let’s start by answering the first question that you probably have: 

“What is Spaced Repetition?” 

Spaced repetition is a system of study that helps us remember things. Everyone remembers what it was like to study and cram for an exam back in high school or college, only to forget everything 15 minutes after the test. 

Spaced rep is totally different. You’re not brute forcing something into your short term memory, it’s much smarter than that.  If you do it right, the memories will last forever. It’s also a lot more fun. 

The basic idea behind spaced repetition is that the best time to study something is right before you’re about to forget it. 

When you think about it, it doesn’t make a lot of sense to continue studying something that you already know — such as your date of birth, or phone number — so there’s also a component of spaced repetition that prioritizes information that you’re likely to be at risk of forgetting, just before you forget it. 

If you’ve used flashcards before, you can think of it like taking the easy flash cards out of your deck and putting them into another deck that you’re going to revisit next week. This is a good idea because your time is much better spent on learning the hard ones than spinning your wheels on the easy ones. 

The good news is that you don’t have to worry about any of this. 

For every individual thing that you want to remember, Spaced Repetition systems keep track of: 

  1. How often you’ve seen it
  2. How recently you’ve seen it
  3. How hard it was for you to remember it

The end result of this is that if something was hard to remember you’ll see it again sooner than something that was easy for you to remember. 

Once you get going it feels a lot like magic. 

Why should we learn about spaced repetition? 

Because human memory is imperfect. If you don’t do anything proactive about your memory, your brain is going to prioritize and hang onto the things that you do most often. 

I find that frequency is a very poor indicator of quality and usefulness, and I’d rather be hands on and proactive about forcing my brain to remember the things that matter to me. 

These can be things like friends birthdays, countries and capitals, or other general trivia — but they can also be far more useful… things that aren’t so easy to Google. 

  • Language learning
  • Book notes and takeaways
  • Personal stories
  • Presentations and speeches
  • Etc. 

Pretty much anything that you think you’d like to remember — that’s what you’ll put into the system. 

In addition to all of the personal benefits, there’s also a meta benefit. If you’re a marketer you can make your marketing better simply by understanding how other people remember things. 

More broadly, you should feel free to use what you learn here on the people around you. Need your kids to remember a few phone numbers for emergencies? Piece of cake, you’ll know how to get that done. Need to memorize a speech coming up for work? Sure thing. 

Having a bad memory is something that a lot of people complain about, but very few actually know how to work on. Your memory is something you can begin to use as a tool with some level of predictability. 

The magic of spaced repetition is that you get a say in all of this. You can choose to make certain things easier to remember. 

I’ll see you in the next video and we’ll get started.

02 - How Does Spaced Repetition Work?

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In this video we’re going to dig a little deeper into the concepts and learn where spaced repetition came from and how it works. 

In a nutshell, spaced repetition is based on the idea that the best time to remember something is right before you’re about to forget it. 

This also means that you shouldn’t waste your time trying to memorize things that you already know, and that it doesn’t really make sense to memorize the same piece of information every day at the same time. 

At this point I think that it’s important to note that what we’re concerned with here is retention, not learning. As I’ll explain later, you shouldn’t really be trying to memorize things that you don’t understand. 

So let’s begin by taking a look at where spaced repetition came from. 

Back in the late 1800s, a German philosopher by the name of Hermann Ebbinghaus was trying to understand how human memory works. 

In particular, he wanted to isolate the processes of “learning” and “forgetting” so that he could figure out how each of them works. If he knew how they worked, he could optimize for them. 

Ebbinghaus had a sneaking suspicion that memory of particular words would be impacted by pre-existing associations: things like personal memories, experiences, or general vocabulary.

He was right. You’re probably able to recall your dad’s name more quickly than you can the barista who makes your morning coffee. That’s because you hear your dads name more often – said another way, the frequency is higher. 

Now imagine that the barista had the same name as your dad. You’d probably be able to remember it better. That’s one of the associations Ebbinghaus was talking about. 

So to avoid this, Ebbinghaus made up a whole bunch of words, about 2300 actually, from fairly random syllables called CVCs (stands for Consonant–Vowel–Consonant). 

Here are a few of his words: 

  • Zuk 
  • Qax
  • Wid
  • Zof

Next, he fired up a metronome and read them outloud, one after another.

After he was through, he’d try to recall as many as he could. What he found was that he forgot things at an exponential rate. 

On a graph, it looks like this: 

The sharpest decline occurs in the first twenty minutes and the decay is significant through the first hour. The curve levels off after about one day.

However, and lucky for us, once we forget something it’s easier to re-learn it. This is called the learning curve, and it’s the 2nd thing that Ebbinghaus figured out. It’s pretty much exactly the same idea. 

The first time you learn information you take in the lions share and each subsequent time you actually leave with smaller and smaller amounts on top of that base. 

Anyway, back to memory. 

The end result of this research was that the best way to strengthen the memory of learned information was to engage in spaced repetition based on active recall. 

Active recall is when you see a question and have to come up with an answer without any help. In contrast, passive recall is something like reading, or multiple choice, where the answer is there and doesn’t have to be produced out of thin air. 

As we posited before, the best time to learn something is just before you’re about to forget it. If we look back to the forgetting curve we can see that each time we repeat the active recall process the curve flattens a little and we slow down the process of forgetting. That’s because every time we recall something we strengthen the memory. 

Each time we strengthen something we can wait a little bit longer to recall it. That is the space in spaced repetition. 

The important principle here is that for long term memory it’s not the number of times that we recall something, it’s the period of time over which we continue to access the information. 

That’s how we make sure we remember something long-term – by remembering it every once in a while when we’re just about to forget it. 

This is what spaced repetition does – and believe me, it works like a charm. 

After I explain this to people, they’re often incredulous. It can’t possibly work, or we’d all have heard of it. 

I know. It’s kind of nuts. And by the way, you’re not the only one who thinks that.. 

In 1988 a leading psych journal published a piece called “The Spacing Effect: A Case Study in the Failure to Apply the Results of Psychological Research."

Alright, now that we know what spaced repetition is and where it came from, we’re ready to get started. I’ll see you in the next video, where we’ll do just that.

03 - Three Rules for Getting Started

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Rule #1 - Don’t try to memorize things that you don’t understand. 

Part of the reason that people love spaced repetition so much is because it makes learning more efficient. You don’t waste time on the things you don’t need to spend time on. 

Presumably the reason you’re doing this in the first place is because you want to be able to put something useful that you’ve learned into practice.

Our first rule is that you have to actually learn whatever it is that you’re trying to memorize. Certain things like numbers, dates, or lists, are fine and dandy, but the types of material that are best suited for spaced repetition are smaller pieces of larger concepts. 

This next part is essential: 

We want to commit knowledge to memory, not representations of knowledge. 

We want to be able to explain, and execute ideas, not just return pre-written sentences about a concept. 

In order to do this we need to focus on active recall, and we need to create dynamic questions. 

If you only have a few flash cards in your deck, you’ll begin to memorize them in the order in which they are presented. 

Additionally, if you always ask yourself the same question in the same way, you’ll memorize the answer to that question, not the fundamental thing that you were trying to recall. 

The end result is that you won’t be able to recall it under a different context. 

It’s the difference between knowing the name of something and the nature of something. 

Rule #2 - Make things as simple as possible, but not simpler. 

Einstein said that, and I think it’s absolutely perfect for this rule. 

With spaced repetition we’re primarily using flashcards, or their digital equivalents. Really, anything that can be phrased in question and answer format can work. 

This rule has to do with how we break down a larger piece of information into smaller fragments that can be memorized over a period of time. 

You don’t just memorize an entire encyclopedia at once. You could, but it would be far more useful to have each individual topic available for use independently. 

An example of a bad question and answer: 

  • What is a lion? 
  • A lion is a large cat with orange and white stripes, big teeth, and the males usually have a large mane. 

This is actually a pretty dense answer with several key pieces of information. If we threw this into our system we’d have a good chance of ending up with brittle knowledge. We might end up memorizing that sentence, instead of memorizing the information that it holds. 

Additionally, having multiple “answers” in a single answer strips us of some of the benefit of spaced rep anyway – namely that of only studying things we need to study, at exactly the time we need to study them. Say we know 2 of the 3 characteristics in that sentence. We don’t need to study those right now. 

It would be much better to create several questions to handle this: 

What kind of animal is a lion? - Cat

Which gender of lion has a mane? - Male 

What colors are typically associated with Lions? - Orange and White 

By doing this we’re not losing any of the information, we’re just making it atomic and specific. Simpler pieces of information are easier to study, easier to remember, and easier to put into practice. 

Rule #3 - Your system is only as good as your routine. 

You can have the absolute best system in the world, with perfectly written questions and answers, neatly organized, and bursting with usefulness, but at the end of the day, in order for it to work you have to sit down and do the routine. 

There are 3 pieces you need to figure out: 

  1. What information you want to memorize
  2. How you’ll get that information into your system 
  3. When, and where you’ll create your review habit 

I think that you could just add random things as you go about your journeys, but like most things, Spaced Repetition is better with some intentionality. 

Figure out ahead of time the types of things you’d like to remember. Maybe that’s a new language. Maybe it’s the name and capital of every country on earth. 

Setting that intention allows us to create meaningful outcomes. We can choose what we want to be able to do and then put together the information that we’ll need. 

The next thing you need to do is figure out how to get the information into Anki, or whatever you decide to use. The next video is dedicated to this part, but I like to have a way to highlight text as i read it, so that i can go back in later and put that onto cards. 

The final thing you need to do is develop the review habit. You need to sit down and review the information. You need to test your active recall, and you need to make sure that you’re strengthening your memories just before you’re about to forget them, which is the whole point. 

There are apps and things you can use for this, and the one we dig into later will help, but you need to just go in with the commitment that you’re going to open your spaced rep app every morning or evening before bed or whatever. For most people it’s just a few minutes per day, as in two or three minutes, not some big commitment.

04 - A System for Collecting Information

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First, let’s figure out what kind of things we should save. It’s a pretty subjective thing, but I can share what I do and maybe it will get you thinking about what you might be able to do. 

The way I work is that I get really interested in certain things for fairly short periods of time. I’m the kind of person that can drive my friends nuts with my constant gear shifting. One week I’m really into stock options, and the next I’m learning about Magic the gathering. I rely on spaced repetition to keep these learned items in my mind. If I didn’t, I’d probably have very little to show for my time, as these interests lead to a lot of research and then go dormant for weeks or months at a time. 

I almost never blindly get interested in something… I’ve normally got a goal in mind. That makes it easy for me to identify pieces of information that I should save to Anki – which is normally anything that helps me complete that goal. 

If I were learning a programming language I’d try to save any new pieces of vocabulary, language syntax, common pieces of software or commonly used services, and/or general concepts. Presumably I’d be learning a new programming language so that I could make something with it. That makes it easy to identify things that I’m likely to need to know in order to do that. 

Now that I have that intention set, I’m able to go out and begin collecting information. For me, this looks like finding articles, videos, podcasts, books, or presentations to consume. 

You can’t simply save everything or your system would be no better than Google. 

Secondly, as we discussed previously, you absolutely need to understand the concepts before you get them into Anki. There is no shortcut here, but there are some tools to help you take what you need from a large corpus of content. 

I save all web articles to a read-it-later service called Instapaper. It’s kind of like an upgraded bookmark with an optimized reading experience. It’s available as a desktop browser plugin and a mobile or tablet app. I use both. 

This enables me to highlight anything I find interesting and want to flag to put into Anki. 

I do most of my discovery and saving on the desktop, but most of the actual reading on mobile. 

While I’m reading, I’ll use the highlight feature to save pieces of information that I’d like to add to Anki. 

Later, when I’m back at my computer, I’ll pop into my Instapaper notes and just scroll through and put things into my system. 

That’s a good process for known quantities, but what about things that are likely to pop up in the future? 

To keep up and current, I subscribe to tons of RSS feeds. I’ve tried tons of RSS readers over the years, but my favorite of all of them is Feedly. Feedly allows me to filter out certain keywords (like podcast, or sponsor) and follow Google Alerts or Twitter accounts for keywords. 

There’s a lot to the Feedly service and this doesn’t even scratch the surface. I plan to do a much deeper dive on Feedly sometime in the future. 

I’m able to highlight there too, but again, I largely use Feedly on my desktop and save the articles I actually want to read to Instapaper, where I’ll use the same process as before. 

If there’s a book I want to read specific to whatever learning project I’m working on, I’ll pick it up on Kindle. As you might imagine – I do this so I can use the built in highlights feature. Once I’m done reading and highlighting I can go to the kindle cloud site and review all of the highlights and add them into my system. 

As you can see, my system handles everything from discovery of new content, all the way to flagging certain pieces of information for input into my spaced repetition system. Even if you don’t use my system, whatever you do settle on will need to handle these stages as well. 

In the next video we’re going to learn about Anki. I’ll see you there.

05 - Beginners Guide to Anki

Download Anki: Ankiweb