12 ms·

Spaced repetition has been all the rage for 20 years now. Dozens of apps, thousands of lectures, and it turns out its not really a silver bullet. There's noth

Spaced repetition has been all the rage for 20 years now. Dozens of apps, thousands of lectures, and it turns out its not really a silver bullet. There's nothing really wrong with it, it's just that people tend to fall off the same way they do on any other education pattern. A couple years ago I was thinking "If Google and Apple really cared about kids they would make a spaced repetition unlock system", where by you have to make note cards every week and then have to answer correctly to get into your phone. (obviously requires some bypass system, other rules, etc) You could probably jury rig it with a popup that comes up after you unlock, but people would never install it anyway.

huhkerrf 1y ago
If you're expecting it to be a silver bullet, then you're in for a bad time. You still have to do the work. It's a lever or a pulley, nothing more.
- jgalt212 1y ago
  > You still have to do the work Spaced repetition is doing the work.
  - antasvara 1y ago
    The "work" is actively trying to recall the information on the card. Spaced repetition is just a more efficient way of doing this than (for example) cycling through every single card, every single day.
    - aswegs8 1y ago
      ...and more efficient than reading long-form text or course material
petesergeant 1y ago
> There's nothing really wrong with it And a gigantic amount right with it. This is a strange comment because it shrugs off something that has been transformative and hugely useful to a lot of people because it doesn’t fix all conceivable problems.
- chjj 1y ago
  I don't think it's a strange comment. He's mostly right (and so are you, but I think you're talking past each other). There's nothing wrong with SRS, and I agree with you that it's basically like cheat codes for memorization, but there is a limit to what most people can do. i.e. most people do tend to drop off. I remember reading some stats from WaniKani (Japanese SRS app) a while back... WaniKani has 60 "levels" to learn 2000+ kanji. Each level takes about a week (there's no skipping ahead), so the material takes about a year of study to complete -- that's if you're going at breakneck pace, which most people aren't. According to the numbers I saw on the WK forums, ~8% of users reach level 30 and less than 1% reach level 60... and that's just to learn as much kanji as a 9th grader. That's to say nothing of the grammar and the 20,000+ vocab words you'll need to SRS to truly learn the language, or the thousands of hours you'll have to spend speaking/listening/reading, immersing yourself in native content, etc. People give up very easily. The language learning community often gives year estimates to reach "near-native level" in a language based on frequency of study. In reality, the process takes a lifetime. I don't know if people truly know what they're signing up for when install those apps and begin studying. It's a lifelong commitment. It's just something you do now, every day. You can stop at any time of course, and most people do (more than 99% of them apparently).
  - chongli 1y ago
    Learning a language as a hobby is tough. If you don't need the language to communicate and survive in your environment then you have essentially zero real motivation to learn it. The problem with spaced repetition systems is that it doesn't supply that extra motivation. You're still just memorizing things in a vacuum. If you truly want to learn a language you need to use it to communicate. That means making friends, travelling, reading books, and consuming other media in that language.
    - Tijdreiziger 1y ago
      You can also be motivated because you like to consume media in the language (relevant for English and Japanese), because you think it will be useful for a job (English) or for travel (French, Spanish, etc.), or simply because you like the language. If you don’t have any of these reasons to motivate you, the question arises of why you’re bothering in the first place.
oliwary 1y ago
I think this is a brilliant idea! Surprised nobody has built it yet. I would definitely use it.
hiatus 1y ago
I would expect the flashcards produced under this regime to be utterly useless, like a flashcard with "A" and the answer is "B", or simple math problems. In other words, Goodhart's law.
- InkCanon 1y ago
  This is a very big problem. Virtually all the results from research here comes from some form of simple word recall. Direct recall occupies some part of real world tasks, but IRL if you're stopped by doing something it's people not because you can't remember it (and you could look it up if you forgot).
  - aswegs8 1y ago
    It's just logical that memorization is useful for broad areas like vocabulary and get progressively worse the more depth is involved, e.g. vocabulary>grammar>maths. The first one doesn't require generalization, the last one most certainly does. Even though I find that SRS leads to good generalization if it is used for relatively shallow conceptual knowledge.
Alex-Programs 1y ago
Spaced repetition is time-optimised, but it isn't self-discipline optimised, nor motivation-optimised. If you're limited by time, it's very efficient, but it drains motivation. If you're anywhere close to being limited by motivation (or, failing that, self-discipline), it just causes burnout and failure. I credit Anki to my success at GCSEs and A Levels despite having a head injury, and I also credit it to me burning out so hard I took a gap year! And I'm enjoying the gap year, but Anki made it a near necessity.
- InkCanon 1y ago
  There was an interesting post here awhile back about autonomy and motivation. The gist was people's motivation is proportional to their autonomy. This is quite intuitive, you can see people are really motivated when they have autonomy (think kids with Minecraft, musicians with instruments). One terrible thing about Anki is that it probably is horrible for autonomy. Quite possibly using anki actually has a negative effect on motivation.
  - url00 1y ago
    That sounds very interesting! Do you still have a link to that post?
    - Tomte 1y ago
      Look up Deci/Ryan, self determination theory.
- maximus-decimus 1y ago
  I don't understand, wouldn't it be worse for motivation to take longer to achieve the same results?
  - avemuri 1y ago
    Motivation is some combination of real and perceived effort Vs expected reward. Shorter isn't always better. For eg. Counting every single calorie is the shorter way to lose weight, but for most people, eating approximately healthy is more optimal from an effort /motivation poi t of view.
InkCanon 1y ago
There's some UX problems of SRS (that I'm working on) that makes it high friction 1) Time taken to create cards 2) Need for self marking 3) Creates a one to one mapping of prompt-answer 4) If you're an autodidact, you have to teach yourself first (alternatively called understanding, scaffolding, etc) More fundamentally, SRS isn't a superpower because it's just very specific to creating a direct prompt retrieval. Generalization is poor. Even creating a graph of knowledge, is a chain of edges between bits of knowledge, isn't done very well here. And I suspect there's a very deep, fundamental difference between recollection knowledge and logical-modeling knowledge. Recollection seems very similar to a dictionary access, and if you recorded the time to recall in humans I suspect they'd all be constant. But learning the knowledge of a logical model, like of a mathematical concept, appears to be vastly different and have very different time to compute. Proponents of SRS will point out logical models need facts as well, like formulas, lemmas, etc. Which is true. But if you already grasped it before you'd grasp it faster the second time. So the practical use of SRS is a significant step above having a very well sorted and labeled notebook, but still way below becoming a genius.
- barrell 1y ago
  Where do we find more about what you’re working on? :)
- nomadpenguin 1y ago
  Poor generalization (overtraining on prompts) and loss of context over time are the biggest issues I've found with them. Slow card creation workflows and needing to rate your own reviews are merely UX issues -- losing context and losing generalization make SRS actively harmful when used for some topics. There's 2 solutions I've thought of but haven't tried implementing: 1. A free-recall based approach. Free recall allows you to operate at a higher level of organization and connect concepts at lower levels. However, how you would schedule SRS with free recall is not clear. 2. Have an LLM generate questions on-the-fly so that you don't overtrain on prompts. You might also instruct the LLM to create questions that connect multiple concepts together. The problem with this approach is that LLMs are still not so good at creating good test questions.
fao_ 1y ago
> Dozens of apps, thousands of lectures, and it turns out its not really a silver bullet. I mean, you say that, but I did mandarin for maybe 6 months, I did reviews for maybe a year or two on and off, I haven't done a review of mandarin for 8, 9 years now and I can still recall quite a bit of it. So for me it's worked quite well.
BeetleB 1y ago
> Dozens of apps, thousands of lectures, and it turns out its not really a silver bullet. Easy statement to make when you're not defining the silver bullet. Kind of like saying dieting turns out not to be a silver bullet. I've used spaced repairing for over 6 years. It's been transformative for me.
- 0xDEAFBEAD 1y ago
  What info did you memorize?
  - BeetleB 1y ago
    Basic undergrad statistics. This doesn't make me better at doing statistics, but now I can understand things I read. Whereas prior to SR, I had learned the material three separate times - always forgot because of lack of use. SR made it stick. Algorithms and data structures. Basics of HTML/CSS/JS. I'm not a frontend developer, but this was enough for me to (mostly) understand colleagues' JS code. And often I would inform him of one of the newer JS features he didn't know of (e.g. null coalescing operator). Does it make me a JS developer? No. But it ensures I'm not useless at it. Python 3.x new features. Simple things like "Stop using os.walk and use scandir instead". A whole lot of Emacs keybindings. I was a heavy Emacs user before SR, but this really helped take it to the next level (I now mostly rely on hydras, so I no longer memorize keystrokes, cut I can't deny its effectiveness). Some amount of elisp. Probably a whole lot more random miscellany I can't recall right now. Basically, what it does is let you retain information without usage. Prior to this, I would mostly retain only things I use (or had used) often. I was in university for over a decade. Took lots of notes. But they're useless if you don't review them. Some years after leaving university I stopped trying to learn anything technical unless I was putting it to immediate use. Why bother if you're going to forget? SR is what let me get back to studying for fun.
    - sireat 1y ago
      I can understand using SR for languages or I suppose geography or history trivia. However, how do you use for skills/domains where you have to actively think? Like in your Python example, knowing about os.scandir() would be a tiny bit helpful before Pathlib. Let's say I put pathlib.Path().iterdir() in my Anki card, what would be the point of that for someone who is happily using glob or rglob? What I mean is that for many domains it seems the challenge is what to put on these Anki cards. Let's go with another example. Let's say you create Anki card Recall = TP / (TP + FN) for your statistics 101. However knowing why and when recall is important would be crucial instead of knowing bare formula.
sn9 1y ago
You say that but it's completely revolutionized the way medical students study. IIRC the effect was so profound they had to modify the structure of some tests or something to that effect. And polyglots have been using SRS for years. As always, the real problem when people fail to do something that works is psychological, not technical. I'd say anyone who made an Ozempic for motivation would make a killing, but I believe it's already a scheduled substance. Maybe one without potential for addiction or abuse. Or maybe an Ozempic for conscientiousness.
- cpburns2009 1y ago
  I'm not so sure. My brother's medical school had to tell students they had to study the actual material rather than Anki decks because so many students were failing tests.
  - sn9 1y ago
    That seems highly atypical. Perhaps they were relying on LLMs to generate decks?
  - pastage 1y ago
    Doing anki cards with words two hours every day, and not doing any reading of material is very detrimental for me. I do not study medicin, but for language I have to actually be able to use what I memorize. Knowing how to use words is harder than it sounds, you need context. A common mistake when constructing sentences is getting the tone wrong and choosing the wrong synonyms.
    - ragazzina 1y ago
      ..this is why you usually have whole sentences on Anki cards, not single words.
      - pastage 1y ago
        Does not always help, but I am not picking. You are right it only fails in 1/100 cards.
dkarl 1y ago
> it turns out its not really a silver bullet One thing that bothers me about SRS is that it doesn't get enough attention from people who understand the difference between memorization and language acquisition. It gets a ton of attention from people who are doing test prep or who get intrinsic reward from their memorization accomplishments. Memorization is not my goal — I want to get better at reading Spanish and French — but I find that drilling on vocabulary and example sentences helps a lot. I compare it to using scaffolding in construction. Scaffolding is not a building. Scaffolding doesn't serve any of the purposes a building does. But if you need to build, expand, or refurbish a building, sometimes building scaffolding in and around it can speed things up a hell of a lot. I wish there were better guidance for using memorization to assist in language learning, but the world seems to be split between people who are satisfied with memorization as their goal (for test prep or intrinsic satisfaction) and people who dismiss memorization entirely because it isn't their goal.
- hiAndrewQuinn 1y ago
  If I weren't already busy enough using Anki to accomplish my own goals, I would almost certainly look into deeply integrating LLM calls into it so that we could e.g. practice writing and speaking with it in a way that is much closer to the kind of immediate feedback loop you get with a tutor. For now, I make do by having Gemini Flash 2.5 open in a separate window and checking my short answer writing responses with that.
IshKebab 1y ago
It's a silver bullet for learning facts. You still have to actually do the learning. Nobody was claiming it would download knowledge into your brain Matrix-style. You'd probably say silver bullets aren't a silver bullet because you still have to load the gun and shoot it.

huhkerrf 1y ago

If you're expecting it to be a silver bullet, then you're in for a bad time. You still have to do the work. It's a lever or a pulley, nothing more.

jgalt212 1y ago
> You still have to do the work Spaced repetition is doing the work.
- antasvara 1y ago
  The "work" is actively trying to recall the information on the card. Spaced repetition is just a more efficient way of doing this than (for example) cycling through every single card, every single day.
  - aswegs8 1y ago
    ...and more efficient than reading long-form text or course material

petesergeant 1y ago

> There's nothing really wrong with it And a gigantic amount right with it. This is a strange comment because it shrugs off something that has been transformative and hugely useful to a lot of people because it doesn’t fix all conceivable problems.

chjj 1y ago
I don't think it's a strange comment. He's mostly right (and so are you, but I think you're talking past each other). There's nothing wrong with SRS, and I agree with you that it's basically like cheat codes for memorization, but there is a limit to what most people can do. i.e. most people do tend to drop off. I remember reading some stats from WaniKani (Japanese SRS app) a while back... WaniKani has 60 "levels" to learn 2000+ kanji. Each level takes about a week (there's no skipping ahead), so the material takes about a year of study to complete -- that's if you're going at breakneck pace, which most people aren't. According to the numbers I saw on the WK forums, ~8% of users reach level 30 and less than 1% reach level 60... and that's just to learn as much kanji as a 9th grader. That's to say nothing of the grammar and the 20,000+ vocab words you'll need to SRS to truly learn the language, or the thousands of hours you'll have to spend speaking/listening/reading, immersing yourself in native content, etc. People give up very easily. The language learning community often gives year estimates to reach "near-native level" in a language based on frequency of study. In reality, the process takes a lifetime. I don't know if people truly know what they're signing up for when install those apps and begin studying. It's a lifelong commitment. It's just something you do now, every day. You can stop at any time of course, and most people do (more than 99% of them apparently).
- chongli 1y ago
  Learning a language as a hobby is tough. If you don't need the language to communicate and survive in your environment then you have essentially zero real motivation to learn it. The problem with spaced repetition systems is that it doesn't supply that extra motivation. You're still just memorizing things in a vacuum. If you truly want to learn a language you need to use it to communicate. That means making friends, travelling, reading books, and consuming other media in that language.
  - Tijdreiziger 1y ago
    You can also be motivated because you like to consume media in the language (relevant for English and Japanese), because you think it will be useful for a job (English) or for travel (French, Spanish, etc.), or simply because you like the language. If you don’t have any of these reasons to motivate you, the question arises of why you’re bothering in the first place.

oliwary 1y ago

I think this is a brilliant idea! Surprised nobody has built it yet. I would definitely use it.

hiatus 1y ago

I would expect the flashcards produced under this regime to be utterly useless, like a flashcard with "A" and the answer is "B", or simple math problems. In other words, Goodhart's law.

InkCanon 1y ago
This is a very big problem. Virtually all the results from research here comes from some form of simple word recall. Direct recall occupies some part of real world tasks, but IRL if you're stopped by doing something it's people not because you can't remember it (and you could look it up if you forgot).
- aswegs8 1y ago
  It's just logical that memorization is useful for broad areas like vocabulary and get progressively worse the more depth is involved, e.g. vocabulary>grammar>maths. The first one doesn't require generalization, the last one most certainly does. Even though I find that SRS leads to good generalization if it is used for relatively shallow conceptual knowledge.

Alex-Programs 1y ago

Spaced repetition is time-optimised, but it isn't self-discipline optimised, nor motivation-optimised. If you're limited by time, it's very efficient, but it drains motivation. If you're anywhere close to being limited by motivation (or, failing that, self-discipline), it just causes burnout and failure. I credit Anki to my success at GCSEs and A Levels despite having a head injury, and I also credit it to me burning out so hard I took a gap year! And I'm enjoying the gap year, but Anki made it a near necessity.

InkCanon 1y ago
There was an interesting post here awhile back about autonomy and motivation. The gist was people's motivation is proportional to their autonomy. This is quite intuitive, you can see people are really motivated when they have autonomy (think kids with Minecraft, musicians with instruments). One terrible thing about Anki is that it probably is horrible for autonomy. Quite possibly using anki actually has a negative effect on motivation.
- url00 1y ago
  That sounds very interesting! Do you still have a link to that post?
  - Tomte 1y ago
    Look up Deci/Ryan, self determination theory.
maximus-decimus 1y ago
I don't understand, wouldn't it be worse for motivation to take longer to achieve the same results?
- avemuri 1y ago
  Motivation is some combination of real and perceived effort Vs expected reward. Shorter isn't always better. For eg. Counting every single calorie is the shorter way to lose weight, but for most people, eating approximately healthy is more optimal from an effort /motivation poi t of view.

InkCanon 1y ago

There's some UX problems of SRS (that I'm working on) that makes it high friction 1) Time taken to create cards 2) Need for self marking 3) Creates a one to one mapping of prompt-answer 4) If you're an autodidact, you have to teach yourself first (alternatively called understanding, scaffolding, etc) More fundamentally, SRS isn't a superpower because it's just very specific to creating a direct prompt retrieval. Generalization is poor. Even creating a graph of knowledge, is a chain of edges between bits of knowledge, isn't done very well here. And I suspect there's a very deep, fundamental difference between recollection knowledge and logical-modeling knowledge. Recollection seems very similar to a dictionary access, and if you recorded the time to recall in humans I suspect they'd all be constant. But learning the knowledge of a logical model, like of a mathematical concept, appears to be vastly different and have very different time to compute. Proponents of SRS will point out logical models need facts as well, like formulas, lemmas, etc. Which is true. But if you already grasped it before you'd grasp it faster the second time. So the practical use of SRS is a significant step above having a very well sorted and labeled notebook, but still way below becoming a genius.

barrell 1y ago
Where do we find more about what you’re working on? :)
nomadpenguin 1y ago
Poor generalization (overtraining on prompts) and loss of context over time are the biggest issues I've found with them. Slow card creation workflows and needing to rate your own reviews are merely UX issues -- losing context and losing generalization make SRS actively harmful when used for some topics. There's 2 solutions I've thought of but haven't tried implementing: 1. A free-recall based approach. Free recall allows you to operate at a higher level of organization and connect concepts at lower levels. However, how you would schedule SRS with free recall is not clear. 2. Have an LLM generate questions on-the-fly so that you don't overtrain on prompts. You might also instruct the LLM to create questions that connect multiple concepts together. The problem with this approach is that LLMs are still not so good at creating good test questions.

fao_ 1y ago

> Dozens of apps, thousands of lectures, and it turns out its not really a silver bullet. I mean, you say that, but I did mandarin for maybe 6 months, I did reviews for maybe a year or two on and off, I haven't done a review of mandarin for 8, 9 years now and I can still recall quite a bit of it. So for me it's worked quite well.

BeetleB 1y ago

> Dozens of apps, thousands of lectures, and it turns out its not really a silver bullet. Easy statement to make when you're not defining the silver bullet. Kind of like saying dieting turns out not to be a silver bullet. I've used spaced repairing for over 6 years. It's been transformative for me.

0xDEAFBEAD 1y ago
What info did you memorize?
- BeetleB 1y ago
  Basic undergrad statistics. This doesn't make me better at doing statistics, but now I can understand things I read. Whereas prior to SR, I had learned the material three separate times - always forgot because of lack of use. SR made it stick. Algorithms and data structures. Basics of HTML/CSS/JS. I'm not a frontend developer, but this was enough for me to (mostly) understand colleagues' JS code. And often I would inform him of one of the newer JS features he didn't know of (e.g. null coalescing operator). Does it make me a JS developer? No. But it ensures I'm not useless at it. Python 3.x new features. Simple things like "Stop using os.walk and use scandir instead". A whole lot of Emacs keybindings. I was a heavy Emacs user before SR, but this really helped take it to the next level (I now mostly rely on hydras, so I no longer memorize keystrokes, cut I can't deny its effectiveness). Some amount of elisp. Probably a whole lot more random miscellany I can't recall right now. Basically, what it does is let you retain information without usage. Prior to this, I would mostly retain only things I use (or had used) often. I was in university for over a decade. Took lots of notes. But they're useless if you don't review them. Some years after leaving university I stopped trying to learn anything technical unless I was putting it to immediate use. Why bother if you're going to forget? SR is what let me get back to studying for fun.
  - sireat 1y ago
    I can understand using SR for languages or I suppose geography or history trivia. However, how do you use for skills/domains where you have to actively think? Like in your Python example, knowing about os.scandir() would be a tiny bit helpful before Pathlib. Let's say I put pathlib.Path().iterdir() in my Anki card, what would be the point of that for someone who is happily using glob or rglob? What I mean is that for many domains it seems the challenge is what to put on these Anki cards. Let's go with another example. Let's say you create Anki card Recall = TP / (TP + FN) for your statistics 101. However knowing why and when recall is important would be crucial instead of knowing bare formula.

sn9 1y ago

You say that but it's completely revolutionized the way medical students study. IIRC the effect was so profound they had to modify the structure of some tests or something to that effect. And polyglots have been using SRS for years. As always, the real problem when people fail to do something that works is psychological, not technical. I'd say anyone who made an Ozempic for motivation would make a killing, but I believe it's already a scheduled substance. Maybe one without potential for addiction or abuse. Or maybe an Ozempic for conscientiousness.

cpburns2009 1y ago
I'm not so sure. My brother's medical school had to tell students they had to study the actual material rather than Anki decks because so many students were failing tests.
- sn9 1y ago
  That seems highly atypical. Perhaps they were relying on LLMs to generate decks?
- pastage 1y ago
  Doing anki cards with words two hours every day, and not doing any reading of material is very detrimental for me. I do not study medicin, but for language I have to actually be able to use what I memorize. Knowing how to use words is harder than it sounds, you need context. A common mistake when constructing sentences is getting the tone wrong and choosing the wrong synonyms.
  - ragazzina 1y ago
    ..this is why you usually have whole sentences on Anki cards, not single words.
    - pastage 1y ago
      Does not always help, but I am not picking. You are right it only fails in 1/100 cards.

dkarl 1y ago

> it turns out its not really a silver bullet One thing that bothers me about SRS is that it doesn't get enough attention from people who understand the difference between memorization and language acquisition. It gets a ton of attention from people who are doing test prep or who get intrinsic reward from their memorization accomplishments. Memorization is not my goal — I want to get better at reading Spanish and French — but I find that drilling on vocabulary and example sentences helps a lot. I compare it to using scaffolding in construction. Scaffolding is not a building. Scaffolding doesn't serve any of the purposes a building does. But if you need to build, expand, or refurbish a building, sometimes building scaffolding in and around it can speed things up a hell of a lot. I wish there were better guidance for using memorization to assist in language learning, but the world seems to be split between people who are satisfied with memorization as their goal (for test prep or intrinsic satisfaction) and people who dismiss memorization entirely because it isn't their goal.

hiAndrewQuinn 1y ago
If I weren't already busy enough using Anki to accomplish my own goals, I would almost certainly look into deeply integrating LLM calls into it so that we could e.g. practice writing and speaking with it in a way that is much closer to the kind of immediate feedback loop you get with a tutor. For now, I make do by having Gemini Flash 2.5 open in a separate window and checking my short answer writing responses with that.

IshKebab 1y ago

It's a silver bullet for learning facts. You still have to actually do the learning. Nobody was claiming it would download knowledge into your brain Matrix-style. You'd probably say silver bullets aren't a silver bullet because you still have to load the gun and shoot it.