
Spaced Repetition - jger15
https://www.gwern.net/Spaced-repetition
======
dguo
I had considered using spaced repetition software for a while after a long
time of being frustrated with my poor memory. I finally started using Anki
last September after reading _Augmenting Long-term Memory_ [1].

I started off with just putting in a new vocabulary word every day and have
been gradually ramping up the amount of info that I put into it. Now, I will
add anything from programming details (e.g. how do you get the number of
characters in a Rust string?) to key facts from the books I read (e.g. in _The
English Patient_ , who does the patient have an affair with?). My review
sessions only take 5-10 minutes a day, and my only regret is not starting this
habit earlier (especially in school). It's incredibly gratifying to review
something, know the answer, and be very aware that without Anki, I would have
forgotten it a long time ago.

[1]:
[http://augmentingcognition.com/ltm.html](http://augmentingcognition.com/ltm.html)

~~~
asymmetric
Do you use multiple decks? I found myself creating several, and then finding
it hard to follow up on many of them. It’s a pity though, because some of the
cards in them were interesting, but the whole deck wasn’t. Maybe I should have
a “misc” one.

~~~
dguo
I don't. Everything goes into a single deck so that my review sessions
interleave[1] topics.

But if you have cards that you don't find interesting or useful anymore, maybe
it'd be better to just delete them.

[1]: [https://www.scientificamerican.com/article/the-
interleaving-...](https://www.scientificamerican.com/article/the-interleaving-
effect-mixing-it-up-boosts-learning/)

~~~
mkl
Doesn't that mean you have to manually put the subject into each card?

E.g. I am currently using Anki to learn more keyboard shortcuts for Bash,
Tmux, and vim, and the deck tells me which program the card is talking about.
I already have to put context for vim visual mode keys in those cards.

Edit: Ah, just saw your other comment about doing something like it with tags.

~~~
dguo
I still manually add context to each card. I want each card to be self-
sufficient, even without any tag data.

------
Buttons840
I've been doing the "30 hour method" as described here: [https://azeria-
labs.com/the-importance-of-deep-work-the-30-h...](https://azeria-labs.com/the-
importance-of-deep-work-the-30-hour-method-for-learning-a-new-skill/)

It's sort of like the Pomodoro technique, except with 30-hour chunks instead
of 30-minute chunks. (Obviously they serve different purposes.)

After studying a topic, while it is still fresh in my mind, I will make a few
entries into my spaced repetition system (org-mode) and then I only review the
entries between each of the 30-hour blocks. This means I'm only reviewing
entries maybe twice a month at most. Yet, the spaced repetition still works
well, and surprisingly, it doesn't take long before I'll only have one or two
entries to review during my rare study sessions.

My point being, even if you study your spaced repetition entries only once a
month, it will still work.

It also helps me not become too obsessed with creating cards for every little
thing. I study a topic for a few weeks, and only at the end do I even think
about spaced repetition and making cards. I review what I've learned (I do
take notes sometimes) and make only a few cards for the most important topics.
Ultimately I'm only thinking about or interacting with spaced repetition
systems one or two days a month. Again, they still work even when used so
rarely.

~~~
srazzaque
+1 for using org-mode and org-drill.

Also means that you can export it all to a well structured PDF and use on any
device that can read PDFs.

Downside is one cannot do drills unless at the PC.

~~~
natmaka
... another downside is that I don't know how to include audio (useful to
learn to pronounce a foreign word).

------
wahnfrieden
If anyone's studying Japanese, I made two iOS apps for spaced repetition
systems specializing in the unique needs of learning Japanese.

The first is a flashcard application called Manabi. It uses a similar
algorithm as Anki with a priority on UX.

[https://manabi.io](https://manabi.io)

The other is Manabi Reader, which complements the flashcard app. It curates
feeds of interesting short-form content, has one-tap dictionary lookups,
optional furigana injection and JLPT level tagging, and it lets you create
flashcards from the words you're learning as you read.

[https://reader.manabi.io](https://reader.manabi.io)

Glad to hear any feedback. I'm currently working on word tracking
functionality for Manabi Reader, to track your reading progress and let you
see which and how many words in an article you should know already vs. words
new to you.

~~~
19f191ty
This looks really cool. Do you have plans for an android version? I wouldn't
mind paying for this.

~~~
wahnfrieden
Sorry, no, they’re completely native apps so I would have to rewrite from
scratch on Android. Would rather focus my time on improving these. Cheers.

~~~
19f191ty
That's too bad :(. Although, I admire your attitude of focusing on improving
the iOS apps rather than branching out.

------
LaundroMat
I mentioned it before, but
[https://ncase.me/remember/](https://ncase.me/remember/) is a verily
accessible read on the subject of spaced repetition.

~~~
DoctorOetker
I have often tried finding the actual research articles that describe the
increasing half-life at the "nearly forgetting" point.

Does anyone know where I can find the equations that model this qualitatively?
(of course there's no expectation that it will list actual quantitative
coefficients for my brain)

~~~
yepguy
Scroll to the bottom of the SuperMemo homepage
([https://www.supermemo.com/en](https://www.supermemo.com/en)) and look at the
list of articles. Some of them are rather informal, others are more academic,
although I'm unsure if they were peer reviewed and published or not.

~~~
DoctorOetker
thanks for roughly pointing me in the right direction, but at [http://super-
memory.com/help/fi.htm](http://super-memory.com/help/fi.htm) it states:

>It is difficult to determine exactly what forgetting index brings the highest
acquisition rate. Simulation experiments have consistently pointed to the
value of 25-30%. You can even plot speed-vs.-forgetting graph using your own
actual learning material in SuperMemo 98 or later using Tools : Statistics :
Simulation. You will probably also arrive at similar results

How can simulation provide us with actual real world data?

How do we know that the forgetting index _sweet spot_ is independent of the
number or even history of recall attempts? If I write R to denote _remembered_
and F as _forgotten_ , then I can imagine RRF, RFR, FRR (variable ordering of
failures for a constant recall rate), and RRF, RFF, FFF (variable retention
rate for different factoids), and R, RR, RRR (number of recall attempts) to
influence the _sweet spot_ level.

Does Anki support plotting plotting such a user's graph? If it does I might
consider rewriting the code such that it can generate multiple plots (to find
sweet spot at N-th recall attempt, N-th recall attempt with M succesful out of
N-1 previous recall attempts, ...)

in the above "simulation experiments" links to [http://super-
memory.com/articles/theory.htm#maximum%20speed](http://super-
memory.com/articles/theory.htm#maximum%20speed)

which doesn't describe any simulation, but just shows a plot, presumably
generated by supermemo statistics for an individual?

If someone has a large homogenous set of Anki cards, I'd like to experiment
myself. Perhaps vocabulary of a foreign language? If I'm going to use a
vocabulary dataset, I'd need a dataset where the responses are sense
disambiguated though (i.e. the sense in parentheses), otherwise I am cramming
wrong associations.

------
hobofan
I find it very exciting that spaced repetition is find some interest here
recently.

There recently was another discussion related to spaced repetition[0], and at
the time I dismissed it. I mostly thought "huh, bad memory never really held
me back in software engineering, so I don't really care", and that with the
fact that my factual memory is probably the worst it has ever been.

Fast forward a month. My biochemistry university studies have started, and I'm
absolutely in love with spaced repetition. It's been one of the best learning
experiences of my life. I don't think I've ever acquired that much (factual)
knowledge about a new field in such a short timeframe, though there a probably
other factors at play too, like motivation.

I write Anki cards on my computer and sync them to my smartphones, and then do
them on my commute and before I go to sleep. Every time I go through some of
my course material and encounter something where I'm not sure what it means, I
note the word (with context) down in my notebook and then later sit down to
write a Anki card for it.

The first exams for the semester are still to come, but largely thanks to
spaced repetition, I feel very confident about them. Really looking forward to
applying it in other parts of my life in the future!

[0]:
[https://news.ycombinator.com/item?id=19529236](https://news.ycombinator.com/item?id=19529236)

------
deepaksurti
A very useful and quick reference to be productive at Anki itself is Anki
Essentials and after working through that, I find my useful using Anki the
right way. Though I don't think having multiple decks is a good idea and have
found using single deck to be much more mimicking how consolidation of what
you have learnt happens in real life, randomly across different subjects.

Does anyone here have tips to memorize the standard library of the programming
language you use say Python using Anki? While yes there is the quick look up
to the lib using a standard dev environment, what I am pointing to is having
to lookup for details for the library function assuming that you know the
function is the right choice because you have added it your long term memory.
If this is useful for nothing, it will be useful at least for the algorithmic
interviews which should be aptly named harakiri :-) [2]

[1] [https://alexvermeer.com/anki-essentials/](https://alexvermeer.com/anki-
essentials/) [2]
[https://en.wikipedia.org/wiki/Seppuku](https://en.wikipedia.org/wiki/Seppuku)

------
jeffshek
If anyone's interested, I've compiled a lot of strategies and tips around
spaced repetition and Anki that I've learned over five years and ~11k cards.

[https://senrigan.io/blog/everything-i-know-strategies-
tips-a...](https://senrigan.io/blog/everything-i-know-strategies-tips-and-
tricks-for-spaced-repetition-anki)

~~~
adbge
Neat! I have a similar page I put up at 10k cards. We should be friends

[http://rs.io/anki-tips/](http://rs.io/anki-tips/)

~~~
jeffshek
YOU'RE ALIVE! I spent a few hours two years ago wondering what had happened to
you (your blog and twitter went quiet). I had presumed the worst.

Thought rs.io is/was really well done, great curated stuff. Added a reference
link to your pages.

Hit me up at jeffshek@gmail.com anytime! I sheepishly already follow you on
Twitter lol.

------
JHonaker
I’ve been using spaced repetition to do algorithm puzzles. I find them really
fun, and I’ll be looking for a job in a little less than a year. So, I thought
I’d get a jumpstart on preparing.

I don’t use them to memorize the answers, but more as a cue to do the problem.
I add 1-5 new cards a day. The cards aren’t facts, but actual problems. It’s
been really effective so far. I can pretty easily recognize what the pieces I
need to apply on novel problems much more quickly.

~~~
mrfusion
Can you share an example card? I can’t picture what you’re doing.

~~~
c13u
Other examples of cards that I made and found useful during my job-hunting
process:
[https://cards.c13u.com/browse[0]](https://cards.c13u.com/browse\[0\])

[0] Disclaimer, I made cards.c13u.com for a class project

~~~
actsof
You copied the link incorrectly, it throws a 404.
[https://cards.c13u.com/browse](https://cards.c13u.com/browse) works instead.

------
FiberBundle
I use Anki, but I have the problem that I tend to associate the specific form
of the question, a particular latex formula etc. with the answer. As soon as I
look at the question or read the first couple of words, the answer already
pops up, so I'm afraid that I don't actually learn to remember the concepts
but rather question/answer pairs. Does anybody have some recommendations for
dealing with this problem?

~~~
Maxbunny
Good recommendations so far, but personally I find one method to be the most
effective : multiple question versions in conjunction with randomization

Say you have decided to brush up on your first grade math, and you make a card
for multiplication. Instead of just making one "2 _2 = 4 " card, you make one
card containing three potential questions, so you add "5 _ 4 = 20" and "3 * 3
= 9" to the _same_ card. Each time this card is scheduled to appear, Anki will
randomly choose one of the questions to display.

This way you prevent your memory from overfitting to the irrelevant context
and force it to remember the actual concept, because you have to use your
knowledge of how multiplication works every time. You have to pick a large
enough selection of possible questions for that to work, for me three is
usually enough. Additional bonus : anki reviews get less tedious, because you
don't feel like always seeing the same old stuff.

Here's a template for creating such cards:
[https://ankiweb.net/shared/info/947272864](https://ankiweb.net/shared/info/947272864)

------
patcon
Oh! cool! As someone who's bad with remembering names (but who feels that
using names is REALLY important to making people feel welcome) I use spaced
repetition to better match names to faces as a Meetup co-organizer.

I basically wrote a CLI tool to auto-generate an Anki deck from a Meetup.com
event URL, using the publicized names and profile pictures :)
[https://github.com/CivicTechTO/anki-meetup-
memorizer](https://github.com/CivicTechTO/anki-meetup-memorizer)

We have a script that runs weekly via CircleCI, before the event, and drops
the file into a GDrive folder for me to easily load up on the way to the
Meetup: [https://github.com/CivicTechTO/civictechto-
scripts/blob/b1cb...](https://github.com/CivicTechTO/civictechto-
scripts/blob/b1cbfe4110a36c553e705fca482b44e5f5b1354e/.circleci/config.yml#L236-L259)

------
znpy
I love the layout of this website and how well it uses the horizontal space.

I wish more websites would create templates like that.

~~~
kreetx
Not so much to complain, but a thing I noticed while scrolling fast is that
the screen is black for a split second, and then text appears. I wonder why
that is?

~~~
pen2l
Probably because he’s using google fonts.

~~~
gwern
It doesn't use Google Fonts, and even if it did, I don't see why that would
cause screen rendering issues on scroll (as opposed to rendering delays on
initial page load).

------
Abishek_Muthian
Here's an obscure video[1] of Jeremy Howard (Fast.ai) talking about how he
used spaced repetition to learn Chinese and which helped him to better other
students learning Chinese in a university in China!

[1]:
[https://www.youtube.com/watch?v=HwH7bJibmdM](https://www.youtube.com/watch?v=HwH7bJibmdM)

------
jbaudanza
I've had very good results using memrise's spaced-repetition tool to learn
Korean vocab. I find it's a good way to get words into this unindexed "staging
area" in my brain. And then when I need them during a real life situation,
they sort of pop into my consciousness out of nowhere.

I also built a tool to build spaced repetition flash cards from the captions
in YouTube videos. This uses the SuperMemo-2 algorithm, the same algorithm as
Anki. This has helped me a lot with my listening comprehension.

[https://www.captionpop.com/flash-
cards/splash](https://www.captionpop.com/flash-cards/splash)

------
azhenley
A great book that covers this topic is _Human Memory_ by Gabriel Radvansky. A
used copy of the second edition goes for around $15.

------
miguelrochefort
What kind of things should everyone memorize using spaced repetition?

Most people seem to use it to learn languages and technical subjects. I'm
looking for things that most people would find useful in their daily lives:

\- Social security number

\- Credit card number

\- Passport number

\- Multiplication tables

\- Unit conversion tables

\- Emergency phone numbers

\- Recovery codes and passwords

\- Basic recipes and cocktails

\- First aid techniques

\- Survival techniques

\- Phonetic alphabet

\- NATO phonetic alphabet

\- Basic words in foreign languages

------
rdfi
Been using space repetition since 2013. It's unbelievably useful. Wrote about
it in my blog with examples: [https://www.blinkingcaret.com/2016/05/04/hack-
your-brain-lea...](https://www.blinkingcaret.com/2016/05/04/hack-your-brain-
learn-faster-better/)

------
dlkf
This is a great essay. An exciting practical use case is seen in Duolingo.
They use a regression model to learn the half-life of individual words for
users.

[0]: [https://www.youtube.com/watch?v=nvgGSg-
VWAE](https://www.youtube.com/watch?v=nvgGSg-VWAE)

------
SpaceManNabs
It is nice that this is reposted so often here. It is quite apposite to the
nature of the phenomenon.

------
ddffre
I have created a flashcards app for Android that tries to use sort of a spaced
repetition system, just if anyone is interested in trying:
[https://play.google.com/store/apps/details?id=flashcards.wor...](https://play.google.com/store/apps/details?id=flashcards.words.words)

------
idearoots
If you are using Evernote, I've built this little tool that adds spaced
repetition and flash cards capabilities to your notes & highlights.
[https://neuracache.com/](https://neuracache.com/)

------
Pmop
So, Vulcan teaching technique works?

