
The Spacing Effect: How to Improve Learning and Maximize Retention - yarapavan
https://fs.blog/2018/12/spacing-effect/
======
tvanantwerp
SRS is very helpful for learning. I've been using it to study different
technical fields and languages.

Nicky Case recently made this interactive explanation of how it works, which
is itself an SRS system:
[https://ncase.me/remember/](https://ncase.me/remember/)

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misiti3780
I have been using SRS for everything in my life for the last 2.5 years and I
have no doubt I will be doing ANKI flash cards on my death-bed someday (as
depressing as that sounds). It's the single most important productivity hack I
have ever discovered (when used effectively). I successfully used ANKI to
learn a 2nd (and now 3rd language) and retain a lot of knowledge I acquire
from books:

Other things I use it for:

* extending my english vocabulary

* wine knowledge

* retaining math theories

* world history

* receipts

~~~
codeisawesome
I think what really puts me off is the effort of building those cards. It’s
not quite a productivity hack if I’m having to sit and spend hours making
those cards (vs. someone making those cards - and effectively - for me in
exchange for $$). I like memrise a lot for some languages though, and they’ve
long been advocates for this technique by building an entire business around
it. Not much good material for math/CS on it last I checked.

~~~
misiti3780
studies have shown that if you do not create the cards yourself, you do not
retain the info as well. there is no free lunch.

~~~
mitchty
Exactly, making the card is half of the trick to remembering. If you can’t
commit to making your own materials you might as well forget about using
things like this. Yes it’s harder, but no there is no shortcut for learning in
life. Just like exercise you can’t fake doing the work.

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kazlock
This gets used a lot in language learning, especially in the Japanese learning
community where people are trying to memorize thousands of Kanji characters.
Like the article says, the idea is that recalling a fact when you are on the
verge of forgetting it causes it to be reinforced, increasing the interval
before you will next forget it. Using the Japanese language SRS tool WaniKani
([https://www.wanikani.com](https://www.wanikani.com)) I’ve memorized around
900 vocab/characters in the past three months (which is actually kind of slow
compared to most people).

This has been a fun experience for me. I’ve always felt like my memory was
poor compared to most people, but now I have proof that with the right
strategy I can remember anything I want.

> Some researchers also believe that semantic priming is a factor.

When learning a new Kanji in WaniKani you are given a mnuemonic to associate
with it. I find that my retention is much better when the mneumonic feels
strongly associated with the shape/meaning/reading of a character.

Another thing that I’ve found helps retention outside of SRS is
using/encountering an item outside of a study session. The surest way for me
to remember a new word is to hear it in a show or song where I fully
understand the context it’s being used in. Also if the thing you’re memorizing
more of an abstract idea, then explaining it to someone else is a great way to
reinforce it for yourself.

~~~
yorwba
When I looked at WaniKani some time ago, I got the impression (based on their
description, I didn't try it) that they first teach you radicals, then kanji
made out of those radicals, then words made out of those kanji. Is that
correct?

I didn't try it because the approach seemed to lack context to me, and also
because I already know Chinese, so learning Kanji wasn't a priority (I wanted
to focus more on pronunciation, vocabulary and grammar). Instead, I built my
own sentence-level SRS by taking examples from the Tatoeba corpus, segmenting
them with Mecab, adding audio using Open JTalk and then scheduling reviews
based on the probability of not knowing one of the words in a sentence. I've
been dog-fooding it for three months now, and in theory I should be able to
understand 14310 sentences from the corpus.

~~~
kazlock
Yeah, it does build up from radicals->kanji->vocab over 60 levels. I agree,
for someone who knows Chinese already WaniKani is probably not the most
effective way to study. But for people who are unfamiliar with the
Chinese/Kanji character set learning radicals first really helps with mentally
parsing characters with high stroke count. However as I’m sure you know Kanji
readings can be a lot different from the Chinese characters they came from, so
there is still some memorization work to be done.

Also WaniKani doesn’t touch on grammar at all, so it works as only a part of
an overall study routine. I do wish there was a similar SRS service for
grammar/reading. Building up your own decks is such a huge amount of work, and
for someone who is just learning it’s nice to have a curated deck that is
verified for correctness. Sounds like you have an awesome system that’s
working for you though.

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Gatsky
I did a big surge of learning this way for a post-graduate exam in 2010. It
was very effective, much better than any of the 'usual' ways of learning.

However, once the exam was over, there was no way I could maintain the 1 hour
plus of card review each day. Eight years later I remember very little of what
I learned.

Admittedly I was studying quite hard, ending up with nearly 4000 cards after 6
weeks, perhaps there is more luck with less intense schedules. The material
was also complex and esoteric.

~~~
jonsen
“Education is what survives when what has been learned has been forgotten.” B.
F. Skinner

~~~
jgamman
anyone quoting BF Skinner should get an Audrey Watters reply: check out
[http://teachingmachin.es/timeline.html](http://teachingmachin.es/timeline.html)

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jodrellblank
Dr Ali Abdaal runs a YouTube channel (about studying medicine at Cambridge
University) and one of his videos is on "Evidence-based revision tips", with
citations for the studies he's working from - here:
[https://www.youtube.com/watch?v=ukLnPbIffxE](https://www.youtube.com/watch?v=ukLnPbIffxE)
it's about 20 minutes.

He says that spaced repetition is effective, but basic repetition of re-
reading, re-watching, re-listening is not effective.

Spaced repetition with "active recall" comes out significantly more effective
- instead of exposing yourself to the same material over and over, challenge
yourself to recall the material at the time when you're on the edge of
forgetting it; the active mental effort of doing that appears to fix
information in memory much more effectively than reading or hearing it again.

A consequence of that is his suggestion that notes and review material should
not be facts you want to remember, but questions that will prompt you to think
and recall what you want to remember. " _Writing questions for yourself makes
you engage in cognitive effort, and the more brainpower it takes to recall a
fact, the better strengthened that connection seems to get, according to the
evidence at least "_.

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PacifyFish
Spaced repetition is so effective. I'm surprised it's not more ubiquitous.

I recently published a Chrome extension to review knowledge in a new browser
tabs after trying and failing to use Anki post-graduation.
[https://chrome.google.com/webstore/detail/forgetmenot/nncbpj...](https://chrome.google.com/webstore/detail/forgetmenot/nncbpjiiekiakcifiiomalecfnipahbj)

Check it out if you have the chance. I'd love some feedback (and for more
people to use spaced repetition in their everyday lives)!

~~~
ValleyOfTheMtns
Any chance of getting this for Firefox?

~~~
PacifyFish
Hm, I'll probably develop mobile before Firefox so FF would be long way out,
but not out of the question! You can follow @ForgetMeNotBot on Twitter for
(very infrequent) updates.

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closed
Useful review. One caution I have while reading posts like this, is that the
author does not distinguish between the testing effect, and the spacing
effect.

While the value of testing (and especially spaced testing) is well established
[1], the value of spaced restudy (e.g. you see both the question and answer
together) is less established (but see this Bjork paper [2], which argues
there is some benefit to spaced restudy).

[1]:
[https://journals.sagepub.com/doi/abs/10.1177/174569161771887...](https://journals.sagepub.com/doi/abs/10.1177/1745691617718873)

[2]:
[https://journals.sagepub.com/doi/10.1177/0956797615617778](https://journals.sagepub.com/doi/10.1177/0956797615617778)

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eddyg
There was a popular discussion on this topic somewhat recently on HN[1] when a
Wired article from 2008 entitled _To Remember Everything You Learn, Surrender
to This Algorithm_ made the front page.

[1]
[https://news.ycombinator.com/item?id=17706776](https://news.ycombinator.com/item?id=17706776)

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michaelcampbell
2 apps I've used in the past for this that I like are mnemosyne
([https://mnemosyne-proj.org](https://mnemosyne-proj.org)) and Anki
([https://apps.ankiweb.net/](https://apps.ankiweb.net/)).

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hevi_jos
[https://www.supermemo.com/en/blog/did-ebbinghaus-invent-
spac...](https://www.supermemo.com/en/blog/did-ebbinghaus-invent-spaced-
repetition)

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SimCity3000
This sounds a lot like learning an instrument. You should be practicing
consistently in short bursts every day. You don't have to practice for more
than an hour or two. The consistency is what's key. You'll develop better
technique faster if you practice 30 minutes a day as opposed to 3.5 hours
every Sunday.

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askafriend
What I'm curious about is how can I use something like this for books, or
podcasts? Re-reading entire books or re-listening to 1hr+ long podcasts is
obviously not realistic.

Should I be re-reading/re-listening to certain chapters? Keep notes and refer
back to them often?

How do you all do this? I'm very curious.

~~~
hevi_jos
There is something called "Mindmaps", learn about it, it is very useful.

With mindmaps and using the "pause" button in a podcast you can take notes
WHILE you listen or read that are minimal. The trick is that you do not need
more than a few words-images-sounds in context to reconstruct all the podcast
or video or book.

What is context? Imagine you have a screw and a piece with a hole on it. Where
the screw goes? There is only one possibility. You do not need to store the
info "where it goes". You can reconstruct it on real time.

With multiple elements interacting, reduction is enormous,in fact neurons work
extracting connections of key elements. Take japanese "r, l sound", because
the language does not make the distinction,a monolingual japanese could not
differentiate between a "Ra" sound and "la" sound. The additional info is of
no use so reural connections prune it.

You hear the additional info, but discharge it.

With context you could reduce information to remember more than two orders of
magnitude(100-1000 times less).

What you do normally is forget most of what you hear. I believe re reading
entire books or podcast is completely realistic if it is a good book that is
important to you. There are not so many.

If you have read lots of books or podcast you know which ones are essential.

For me for example it could be "The C programming language" or "Structure and
interpretation of computer programs". I have created a C and LISP compiler so
those books are sacred. For Einstein, it was Newton's or Faraday's work.

I read books that I could reread 5 times and I learn something important and
new every time. As I get deeper, I become a master that could understand
concepts and ideas that myself as a novice could not grasp.

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fatnoah
Interesting. This is basically something I learned in college and am
relearning through necessity with my son (11 years old), who has ADHD. Long
study and homework sessions are impossible and, for him, tremendously
discouraging. We've learned to take things in 15-30 minute chunks with breaks
in between and we spread things over several days and the results are
positive. Getting homework and projects done isn't such a chore and he feels
better about himself since he's better prepared for tests.

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james_s_tayler
I used Anki back in 2008 to help me learn Japanese. The best result was
memorizing 10,000 vocab inside a 12 month period during my second year of
study. That did phenomenal things for my Japanese in combination with decent
amounts of conversation.

The power of SRS if you are someone who can take a little bit of pain and who
is good at devising learning strategies is off the charts.

I guess the best way I can put it is there are some things for which the
traditional model of learning would only take you so far but that through a
cleverly devised SRS strategy you could take yourself to places that would be
traditionally not attainable for you.

Maybe that's a bad explanation, I don't really think I'm doing it justice.

Something I've settled on attempting in 2019 through SRS is learning
psychology. Now SRS is only ever PART of a strategy, it's never the whole
thing. But my strategy to get me to the next level that just reading pop
psychology books isn't getting me to is that memorize all the replicated and
highly cited studies in psychology across as many branches of it as possible.
This takes the format of remembering the names of the study/paper, the year it
was published, who the authors were, what journal it was published in. The
second part is memorizing and being able to verbalize a summary of the the
study and it's conclusions.

Think what you will about what that will do for my ability to understand
psychology but I can tell you this for sure: rote memorization of all the
facts then frees your mind up to get to the next level then connecting all the
dots between the facts. People often criticize rote learning because they
think learning is more about connecting the dots and that's what we should
focus on. It's exactly backwards. First focus on getting all the dots into
your head and then inferences start to come thick and fast naturally.

The key to devising an SRS strategy is think in terms of "pieces of
information" and to find good sets of "pieces of information" that have
extremely good power to weight ratio.

There's two things I'll say there... You COULD use SRS to memorize an entire
introductory psych textbook. You COULD. But it would be the exact wrong way to
go about it. If you memorize the relevant category of information you can use
that to Intuit all the explanations .

The other thing to say is the "pieces of information" should have the same
shape. They should be in the same category. They shouldn't be random, but
highly cohesive. For medicine this would be like you start with anatomy first
and you do all of that before moving on. You go in layers.

The next key is then your search stategy on how to locate the information.

The next key is defining different phases of your strategy which boils down to
figuring out which set of pieces of information to after in which order to
achieve which specific goals.

