Spaced Repetition Software
Show Notes
Popular Spaced Repetition Software (SRS)
Other software that uses Spaced Repetition
Memory resources
- Want to Remember Everything You'll Ever Learn? Surrender to This Algorithm (article) by Gary Wolf
- The true history of spaced repetition (article) by Piotr Wozniak
- Spaced Repetition for Efficient Learning (article) by Gwern
- Effective learning: Twenty rules of formulating knowledge (article) by Piotr Wozniak
- The Case For First-Brain Memory (article) by Tasshin Fogleman
- Moonwalking with Einstein (book) by Joshua Foer (amazon goodreads)
Learning Chinese characters
- The Marilyn Method (article) by Serge Gorodish
- Mandarin Blueprint (course based on The Marilyn Method) by Luke Neale and Phil Crimmins
Music
- Intro music: Vlog Music Cafe Type Hip-Hop Instrumental Chill Lo-Fi Beat by Oliwia Orłowska
- Outro music: Game Over [Super Mario World Lofi/hiphop remix] by Neighborhood Vandal
Transcript
Ulysse: Hey, this is the Growth Podcast with your hosts, Ben and Brendon. This episode, we'll be talking about spaced repetition software or: what's the capital of Azerbaijan.
Brendon: Ben and I are very excited about spaced repetition systems, which are a class of software applications that allows people to remember whatever they want for whatever period of time they want to remember it. I think that's a really powerful ability that is beginning to become a bit more popular. For example, medical students studying for the MCAT have started adopting spaced repetition systems a lot because they make it much easier to remember the enormous volume of information you need to retain in order to get a good score on the MCAT. And I'm also personally hopeful that spaced repetition can have a positive impact on society by going more into the mainstream, and for example, perhaps even affecting things like the education system, because spaced repetition systems can help people remember knowledge, skills, and memories for a lifetime, instead of just learning all of these things at once and then forgetting much of what you learn right after you learn it, and forgetting much of what you learned right after you've learned it is closely related to one of the fundamental concepts around what spaced repetition is. That concept is the forgetting curve.
Ulysse: Right. So, the forgetting curve was this observation that when you're trying to learn something, people generally remember something fairly well shortly after learning it or memorizing it, but then as time goes on, they forget. And they forget very fast. There's this exponential drop-off where, only after a couple of days, if you don't revisit some information, unless it was exceedingly visceral to you, you'll probably have forgotten it. And so, from the forgetting curve, what emerged was this idea of the spacing effect. The spacing effect is this observation that people generally remember things best, not when they cram it all in the beginning and not when they revisit it at regular intervals like every day or every week, but actually when they revisit it with increasing periods over time. So, for example, if you learn something one day, you might revisit the information and try to test yourself on it a day later.
Ulysse: Then two days later, and then five days and 10 days and 25 days until eventually, maybe you won't see that information for 5 or 10 years, but there's a pretty good chance that you'll remember it. So, that's the spacing effect. And then, from the spacing effect, this guy, Piotr Wozniak, I think he was Polish and trying to learn English, he came up with this specific algorithm for using this observation and then tested it with flashcards and eventually made some computer software to automate the entire process. That software it's called SuperMemo, and to my knowledge, it was the first computer software that implements spaced repetition, or basically using this spacing effect to memorize things. After SuperMemo, a bunch of other software popped up like Duolingo uses spaced repetition. There's this really common software called Anki, which both Brendon and I tend to use for this kind of thing. You see it all over the place.
Brendon: Yeah. I think spaced repetition is also making its way into a lot of niche shops that specialize in teaching people certain things. For example, it's even found its way into Skritter, which is this application that tries to teach people the stroke order when they're learning Chinese characters. I think that probably relates very closely to what you're working on, Ben, which is picking up a new language, Mandarin.
Ulysse: Right. I've been using the spaced repetition software Anki, which I mentioned before, to learn Chinese. So, this can help in all dimensions of language acquisition, like remembering the meaning of things, remembering the shape of things like the Chinese characters, remembering the sound, and also remembering the grammar points. The software makes it easy to create front and backs of flashcards. And so, the front in this case might be literally a Chinese character and then I'll be testing myself on what it means or what it sounds like or something like that. So, that's going back to the spacing effect. This is just one example of me reviewing the material.
Ulysse: So, spaced repetition software is both the algorithm underneath that sort of makes sure you're tested on each piece of knowledge at the right time, according to the spacing effect, but it's also, like I said, the ecosystem around it, all the tools and software that you might want to get content, test yourself on content, etc.
Brendon: Right. So, spaced repetition helps you remember stuff in the form of active recall, in which there's a prompt and then there's an answer that you have to provide. Yeah. In spaced repetition software, there might be a Chinese character and then the answer that you're supposed to provide would be say the definition of that particular character. Most spaced repetition software asks you to report how well you remembered something and then these software applications actually use algorithms based on your input, like whether or not you remembered something and also how well you remembered it. They use this input to try to guess when you're going to forget the material next. So, of course, if you say you remember something really strongly, then it's likely that you won't need to be prompted to recall the material again in the near future.
Brendon: So, the point here is for spaced repetition software to prompt you to remember things right before you're about to forget them, such that all that information will remain in your memory. And also, it's really efficient to keep that information in your memory, because of course, you could remember something if you reviewed it every single day, but that would just take a lot of time, especially if you're trying to remember a large volume of information. And in fact, I think when I used to use SuperMemo, I recall that there was this percentage threshold you could set where if you wanted the software to be more aggressive about helping you keep things in your memory, you could say, “Hey, I want to try to remember 98% of all of the material I'm trying to learn.”
Brendon: So, the software might prompt you more frequently to review certain concepts so that approximately, you'll shoot for keeping 98% of everything you're learning in your head. I think that's really interesting. If you're studying for the MCAT, you might want to, as you approach the test state, increase that to a really high threshold so you're getting a lot of reviews and so then you can go into the test confident that you are remembering all of the volume information you need to know.
Ulysse: Speaking to that, Gwern from gwern.net fame, he had some stat where he figured out that it takes about five minutes for him to memorize a card through all the reviews he'll do for a card over several years.
Brendon: That's pretty cool.
Ulysse: So, his heuristic was, if anything takes longer than five minutes to look up, then I should probably put it in Anki.
Brendon: Oh. That's a very good heuristic.
Ulysse: Yeah. If it doesn't, then what am I doing with my time? I know you've also used spaced repetition for stuff in the past. How have you used it?
Brendon: I would say that one of the most important things I used spaced repetition for was to memorize all of the different countries in the world and be able to identify them on a map. I was actually taking this international relations course, and everyone was given an unlabeled map of the world and had to identify a bunch of different countries on it. So, I found that spaced repetition was really, really great for this. I personally used the software Anki, which is I think by far the most popular spaced repetition software. They have a shared decks feature where you can get decks of flashcards that people have just released out there for anyone to use. So, what I did was I just found an appropriate bunch of shared flashcards that had all the countries in the world that I think were UN member nations.
Brendon: They already had the country, it was unlabeled, and then the answer was just the name of the country with the correct spelling. So, yeah. I mean, I found that made it super easy for me to get started with memorizing the countries. Yeah, it was great. I think the problem is sometimes spaced repetition is used for things like memorizing all the countries in the world and sometimes you've got to really think about whether or not you actually want to persist that knowledge into long-term memory because there is an associated time investment. At the time, that was the only thing I was using Anki for, was just to keep all these countries in my head, nothing else.
Brendon: So, I guess I wasn't very incentivized to continue to use Anki because I felt it might be useful, but it would just require daily commitment of checking Anki just for the sole purpose of memorizing the world's countries, which these days we have Google at the tip of our fingers on our phones. So, it may not be as necessary to memorize certain bodies of knowledge, but maybe I'm wrong on that because I know you might, for instance, see the value of memorizing ... it might be beneficial to know all the U.S. states or something.
Ulysse: There's that phrase I've read on the internet that's like “He was so busy trying to see how he could, that he never asked if he should.” Or something along those lines. Yeah. I think spaced repetition software is no exception to using your time well. So, you should totally only memorize things that you actually need to know. Piotr Wozniak has some bit where he talks about how reviewing all these facts in quick succession can maybe activate different parts of your mind together and create interesting thoughts, but honestly, I've never seen that. Yeah. I think there are better techniques for that.
Ulysse: Yeah. I've also tried memorizing all the countries and world leaders and general longitude and latitude lines. I was reading this book 20,000 leagues under the sea and it seemed useful to know where things were longitude and latitude wise, but it totally wasn't. I could just look it up on Google Maps.
Brendon: Yeah. I'm curious, which of those do you actually continue to study in Anki?
Ulysse: Yeah. The ones that have been most useful to me are probably hot keys in the different computer programs I use, the language learning features like I was mentioning before the Chinese stuff, and maybe that's it. I feel like everything else has been superfluous. I know a lot of people use Anki for learning general knowledge, like if you're taking a PhD, but I generally have found that I do much better on the simple flashcards, like country-capital, Chinese character-Chinese definition, that kind of stuff.
Brendon: Yeah. I think that makes sense because you use computer hot keys very often. Also, for someone who's trying to learn a new language, they want all of that information at the front of their mind. Whereas, if something's like various countries around the world, how often do you actually need to recall some obscure country names? Azerbaijan or something. That never comes up in conversation.
Ulysse: What do you have against Azerbaijan?
Brendon: Yeah.
Ulysse: I'm just kidding.
Brendon: I think it's really cool that ... I feel like in recent years it's become basically possible for people to remember whatever they want. I think that, around the same time, it's also been possible for people to not remember whatever they want and still be able to perform tasks. You have the rise of the internet and things like say Stack Overflow for programmers, and at the same time you have rising interest in ancient memory techniques like Moonwalking with Einstein is this book I think that became somewhat popular that covers the use of memory palaces to remember various types of specific information like phone numbers, faces, facts, things that would otherwise potentially be a little bit hard to memorize, especially on first pass. So, memory techniques like that combined with spaced repetition to reinforce your memory of a memory palace. Things like that, when you combine memory techniques and easily accessible reference materials and things that share decks with spaced repetition, it becomes possible to basically just remember incredible volumes of information.
Ulysse: Right. The technique I used to remember the Chinese characters is essentially some hybrid of using Anki as spaced repetition software and then using some spatial memory palace technique idea to remember how the sound, the meaning, and the shape of the character all fit together.
Brendon: Yeah. That's definitely really cool. I had not thought of that before as a way to learn foreign languages, or Mandarin specifically.
Ulysse: Yeah. It's a really interesting frontier. I think there's some kind of abstraction where Anki is like a container for another memory test. So, the memory tests might be the memory palace or, in my case, the movie scene that I constructed to remember the Chinese character shape, sound, and meaning.
Brendon: Or even like instead of a memory palace, a common memory technique would also do the case in that trick, and then you could just put that into Anki and then I think that would do a good job of reinforcing the memory.
Ulysse: Right. Right. You can just use some kind of basic mnemonic like, “Oh, this word sounds like this other word and that's associated with the meaning, so I'll just use that.” Yeah. There's tons of mnemonics you can use to remember stuff.
Brendon: But yeah. I like this way of looking at Anki as, I think you said, a container for memory tasks. Yeah. Some like high level broadly applicable memory tool. Then, within that for the types of information you want to store, you may have to do more specific optimizations in terms of learning different things. I mean, I think that's kind of related to the ecosystem I think you mentioned earlier. Although, when you said ecosystem, I got the sense that you were talking maybe more about like audio files to learn Mandarin rather than like employing specific memory techniques to apply to certain types of knowledge.
Ulysse: I just meant, while you might have an image viewer and a sound player and a way of viewing texts in different fonts, generally they're not all in the same tool except if you're talking about the web browser. And that's actually what Anki does. It just uses an embedded web browser generally to show the content that you have in your decks, but as you were mentioning, it's more than that. It's the shared decks where you can leverage the work of others. Also, it's non-prescriptive so you can introduce your own memory techniques. It's very flexible.
Ulysse: Thanks for listening. There's so much literature out there on spaced repetition, and spaced repetition is only one piece of a much greater body of knowledge. In the show notes, we've included links to the software we mentioned in the episode as well as to resources for learning more. The beautiful intro music to this episode was created by Oliwia Orłowska. This relaxing melody is by Neighborhood Vandal. Links to both of these songs can also be found in the show notes.
To hear more, subscribe to my newsletter or follow me on Twitter.