Efficient Spaced Repetition

You gained’t get smarter by drilling IQ checks or taking part in the violin. Twin n-back
probably gained’t enhance your working reminiscence. However you’ll be able to keep in mind something
you select to with spaced repetition.

Spaced repetition is, by far, the simplest cognitive hack I’ve used. It
was that I’d learn a e-book and afterwards keep in mind nearly
nothing. Generally I’d take Kindle highlights, or notes, however by no means evaluate
them. And I hoped that although I couldn’t essentially identify what I recalled
(as a result of whose reminiscence has an index?) that in some way the vital data was
woven into my information, tacitly. That is largely a cope.

I like studying, and spaced repetition has helped me turn out to be extraordinarily good at
it. Nevertheless it took a very long time to turn out to be efficient at it. There’s lots of recommendation
on the Web on the way to do it successfully, most of which is phrased in phrases
of very common ideas, however only a few concrete examples. However what folks
battle with is: how do I flip this particular, concrete piece of data
right into a set of flashcards?

This publish describes the foundations I take advantage of to write down efficient flashcards, with as many
examples as I might moderately discover.

1. Overview of Spaced Repetition
2. Limiting Factors
   1. Habit Formation
   2. Card-Writing Skills
3. Words of Encouragement
4. Rules
   1. Rule: Understand First
   2. Rule: Be Honest
   3. Rule: Keep It Fun
   4. Rule: Repeat Yourself
   5. Rule: Organize by Source
   6. Rule: Write Atomic Flashcards
   7. Rule: Write Two-Way Questions
   8. Rule: Ask Questions in Multiple Ways
   9. Rule: Concept Graphs
   10. Rule: Learning Hierarchies
   11. Rule: Learning Sequences
5. Examples
   1. Example: Magma Formation
   2. Example: Plate Tectonics
   3. Example: Neural Cells
   4. Example: Neuron Types
   5. Example: Vector Spaces
   6. Example: Parity Group
   7. Example: Logical Consequence
   8. Example: Periodization
   9. Example: Rational Numbers
   10. Example: Regular Expressions
   11. Example: Voltage
   12. Example: Isomers
   13. Example: Months of the Year
   14. Example: Powers of Two
   15. Example: Rilke
6. Scripts
   1. Sequence Script
   2. Poetry Script
7. Software
8. Prior Art
9. Conclusion

The concept is mechanically quite simple: as you be taught issues, you write
flashcards, that are query/reply pairs. Then you definitely evaluate them: you have a look at
the query, recall the reply, and switch the cardboard over to see the reply. Then
you grade your self: did you recall accurately or incorrectly?

In case you hold recalling accurately, the evaluate interval grows longer; should you get it
mistaken, the interval will get shorter.

Some folks use paper playing cards, most individuals use software program corresponding to Anki,
as a result of the algorithm schedules opinions effectively, so that you don’t over-review
materials. Except you’ve got a paper fetish, simply use software program.

In case you’re so good, why aren’t you wealthy? Or: if spaced repetition is so
efficient, why doesn’t everybody do it? Why isn’t it as widespread as consuming
espresso?

There are two fundamental limiting elements to efficient spaced repetition.

Behavior Formation

For spaced repetition to be helpful, it must be a behavior. I drill flashcards
each day as a part of my morning routine. However behavior formation is troublesome,
doubly so for individuals who have ADHD or are low in conscientiousness.

The rationale it’s important to do it each day is that the spaced repetition algorithm
schedules the opinions for you, releasing you from having to do this manually. However
you don’t know what playing cards are due in a given day till you open the app. And if
you skip a day, these playing cards pile up and are due the subsequent day.

A standard failure mode (and I did this greater than as soon as, earlier than I acquired the hold of
it) is to make use of Anki for 2 weeks, then drop it, and choose it again up six months
later solely to seek out you’ve got 600 playing cards due for evaluate. This isn’t encouraging,
and it defeats the purpose of spaced repetition, which is to evaluate the playing cards on
the intervals the algorithm chooses.

I don’t have a lot recommendation on this space, besides that when you’ve got persistent
issues with conscientiousness, untreated ADHD and many others. it’s best to tackle that
first.

Card-Writing Expertise

Writing efficient flashcards is a talent that took me some time to amass. Lots of
the playing cards I wrote within the first 4 or six months of utilizing spaced repetition
persistently turned out just about ineffective, and this may be irritating. The
fundamental purpose to write down this publish was to speak the teachings I learnt so that you
can bounce in to utilizing spaced repetition successfully from the beginning.

One purpose this may be irritating is you’ll typically keep in mind a flashcard for the
first few weeks of it (once you’re seeing it with excessive frequency), however after a
couple of months, you begin failing it. It didn’t take root in your long run
reminiscence, as a result of it was poorly written indirectly. And this lengthy suggestions cycle
means it takes time to amass these abilities by means of trial and error.

Studying is an automated, instinctual course of. It’s a elementary function of
intelligence. It’s a testomony to how dangerous education is that individuals assume they
must have a particular type of mind to be taught successfully, and that the thought of
studying triggers aversion in folks. Bear in mind the phrases of Feynman: “what one
idiot can do, one other can”.

Listed here are my guidelines for efficient spaced repetition.

The principles are sorted by applicability (however not essentially significance), with the
extra common ones first, and most particular ones final.

As a result of most of the examples contain a number of guidelines on the identical time, I made a decision
to record the examples individually from the record of guidelines.

Rule: Perceive First

Don’t attempt to memorize what you don’t perceive. The ideas ought to be clear in
your head earlier than you attempt to commit them to reminiscence. “Clear” could be a fuzzy
factor. What I are inclined to do is: dig, increase, and make clear the textual content till I’m
comfy I’ve an excellent grasp of this area of the idea graph, after which
write the flashcards.

Usually, when studying a e-book, you’ll be able to’t write the flashcards precisely as you learn
the textual content, as a result of additional data can make clear or tie collectively vital
ideas. It may be helpful to maintain a scratchpad the place you write tentative
flashcard textual content as you learn a chapter, and on the finish you set up and
re-organize your scratchpad till you’ll be able to commit it to flashcards.

Rule: Be Trustworthy

The software program doesn’t know whether or not you recalled one thing accurately or not. You
are solely accountable to your self. In case you recalled one thing mistaken, or not fairly
proper, err on the aspect of warning and mark it forgotten.

Rule: Maintain It Enjoyable

That is essential to sustaining the behavior. If reviewing flashcards appears like a
chore, you’ll turn out to be averse to doing it.

I used to continuously have this drawback. I solved it in a number of methods:

1. Having a various information base you’re drilling helps, so you aren’t bored
   by going by means of the identical subject for a very long time. Usually, spaced repetition
   software program will shuffle the playing cards, in order that should you’re drilling all of the playing cards
   throughout all decks, you may be stunned typically.
2. A standard supply of frustration is playing cards which might be too lengthy to recall rapidly,
   and thus really feel like a chore. Break massive playing cards down into smaller playing cards. It feels
   good to have the ability to fly by means of the playing cards rapidly.
3. Playing cards which might be troublesome to recall are very irritating. I solved this by
   making use of the foundations described on this publish.

Rule: Repeat Your self

Reminiscence is frequency occasions quantity. Particular person playing cards ought to be extraordinarily transient,
however your deck as an entire will be as repetitive as you need.

Rule: Set up by Supply

Set up content material by supply, not subject.

The reason being you’ll typically herald data from a number of sources: a number of
textbooks, plus Wikipedia, plus lecture notes, and many others. Every considered one of these sources
possible has a distinct method of organizing information.

Don’t waste time looking for the proper ontology.

Make a deck for every supply. Within the case of textbooks, make a sub-deck for every
chapter. Within the case of math textbooks, probably make a sub-sub-deck in every
chapter to place theorem playing cards.

This additionally makes it simpler to maintain observe of how far alongside you bought right into a textual content.

Rule: Write Atomic Flashcards

Playing cards ought to be brief. They need to consult with as little data as
potential. They need to be like chemical bonds, linking particular person atoms of
information.

That is crucial factor. By far the worst failure mode is to
put an excessive amount of in a flashcard.

There’s two causes for this rule:

1. Bigger playing cards are more durable to recollect.
2. It’s more durable to objectively grade your self: once you reveal the reply, you
   might need acquired some issues proper and a few issues mistaken. In case you click on overlook,
   you may be over-reviewing the components you already know. In case you click on
   remembered, you’ll under-review the components you forgot.

There’s one exception to this: you’ll be able to have massive playing cards should you even have smaller
playing cards that add as much as the identical data. You may consider the bigger card as
testing that you would be able to collate the data from the smaller playing cards.

Rule: Write Two-Method Questions

When potential, ask questions in two instructions.

Each time you’ve got a time period with a definition, the apparent factor to do is to ask
for the definition from the time period, e.g.:

Q: What’s the order of a bunch?

A: The cardinality of its underlying set.

However you can too ask for the time period from the definition, e.g.:

Q: What’s the time period for the cardinality of a bunch?

A: The group’s order.

When you’ve got some notation, like $mathbb{R}$ for the actual numbers, or $dim V$
for the dimension of a vector house, the pure factor to ask is what the
notation means.

Q: What does $mathbb{R}$ stand for?

A: The set of actual numbers.

It’s also possible to ask the query backwards:

Q: What’s the notation for the set of actual numbers?

A: $mathbb{R}$

Rule: Ask Questions in A number of Methods

Ask questions in a number of methods. Ask for formal and casual definitions of
phrases. Ask for the formal and casual statements of a theorem. Ask questions
forwards and backwards. Add contextual questions: “what’s the intutition for
[concept]?”. Add questions that hyperlink completely different ideas throughout your information
graph.

The extra interlinked your information graph is, the higher.

Rule: Idea Graphs

It could possibly assist to visualise the ideas you’re buying as being like a graph,
the place every node represents a discrete idea having sure properties, and the
edges within the graphs are questions which get you from one idea to a different.

Rule: Studying Hierarchies

A number of information is hierarchical, of the shape “Foo will be both A, B, or C”,
or, dually, “A is a type of Foo”. By analogy to OOP: these ideas are joined
by superclass and subclass relations.

The concept is to ask questons within the prime down path (“What are the subclasses of
Foo?”) and the bottom-up path (“What’s Bar a subclass of?”).

This ties into protecting flashcards atomic. Even when some data isn’t
hierarchical, intrinsically, breaking down massive flashcards into smaller
flashcards is basically constructing a hierarchy of flashcards.

Rule: Studying Sequences

Usually, to be taught a sequence $(A_1, dots, A_n)$, you need to generate the
following flashcards for every $i in [1,n]$:

You may additionally need:

1. A take a look at card: a flashcard asking you to recite the sequence from starting
   to finish.
2. A cloze sequence: flashcard with a cloze deletion for every factor within the
   sequence, to fill within the clean given the context.

The sequence script can generate these for you.

How thorough you need to be depends upon the character of the data. Most of
the time I take advantage of a cloze card and a take a look at card.

One other sort of card you would possibly use (I take advantage of this to memorize poems) is a card that
provides you some context (the earlier one or two gadgets within the sequence) and asks
you to fill within the clean. For instance, should you needed to be taught the sequence (A,
B, C, D), you might need these flashcards:

The poetry script can generate these for you.

Many of those examples are overkill: we gather much more flashcards than the
topic deserves. However that is for example the overall guidelines. With expertise,
you’ll be able to be taught what number of questions a specific subject requires, and completely different
volumes of your information graph shall be kind of interlinked.

Instance: Magma Formation

From my geology notes:

Let’s break this down hierarchically. We need to memorize three issues:

1. What magma is.
2. The way it varieties.
3. The place it varieties.

First, the definition:

Second, we need to know the way magma varieties. A standard mistake right here can be to place
the magma-forming processes and their explanations in the identical
flashcard. Slightly, to maintain every card as small as potential, we need to separate
the record of processes from their definitions.

So we first as for an inventory of mechanisms:

After which we ask for a proof of every. We don’t really want to ask why
including temperature melts rock:

Third: the place magma is discovered. Once more, we separate the record from the small print:

Then we ask for particulars. For every place the place magma varieties, we ask each which
processes are concerned, and what the total causal clarification is. We additionally ask the
query backward: which locations contain a given course of.

We are able to visualize the ensuing information graph like this:

Instance: Plate Tectonics

Right here’s the data:

Making use of the rule that playing cards ought to be two-way, we would like two flashcards for the
time period ‘plate boundary’.

For the several types of plate boundary, we solely ask the query within the
top-down path (we don’t must ask “what sort of factor is a rework
boundary?”, for the reason that identify type of provides it away):

For every type of plate boundary, we additionally ask the query in two methods:

Graphically, right here’s how the questions hyperlink the ideas within the information graph:

Instance: Neural Cells

Visually:

We first write the top-down questions:

And the bottom-up questions. We don’t ask these when the solutions are apparent:
“what are microglia/macroglia a type of” has an apparent reply.

Instance: Neuron Sorts

This can be a transient instance about protecting playing cards brief and utilizing hierarchies to interrupt
issues down.

From my neuroscience notes:

Let’s begin by doing this the mistaken method, by loading an excessive amount of data
into one card.

Let’s first break this down by separating phrases from definitions:

Now we ask the questions within the backward path: from the definition to the time period:

Instance: Vector Areas

Right here’s what we need to be taught:

Now we have to interrupt this down. Severely. We’ll do that step-by-step.

First, we now have to separate the casual (intuitive) and formal definitions:

We add one transient query about notation (you might select to skip this one, it’s
an instance):

Now we ask concerning the signatures of the operations:

Subsequent, we ask for the axioms:

Lastly, we ask what every axiom means:

Graphically, you’ll be able to attempt visualizing the flashcards and their relationships like this:

If you wish to be additional thorough, you can too write the backwards questions:

Instance: Parity Group

We are able to flip this into the next flashcards:

Instance: Logical Consequence

From my notes on logic:

We start with probably the most fundamental query:

Then we ask questions particularly about semantic consequence:

After which about syntactic consequence:

Instance: Periodization

Timelines are an amazing instance of how breaking data down hierarchically
may also help you be taught lengthy sequences. Generally the breakdown is already accomplished for
us.

We need to be taught the next issues:

1. What the geologic time scale is.
2. The way it divides the Earth’s historical past.
3. The 4 eons.

Let’s start with the only flashcards, the definition of the GTS:

The subdivisions kind a sequence, from oldest to most up-to-date: eon, period, interval,
epoch. So let’s feed it into the sequence script. Right here’s the
enter:

Geologic Time Items
Eon
Period
Interval
Epoch

Working cat models.txt | ./sequence.py > models.csv and importing models.csv
into Mochi, we get these flashcards:

You most likely don’t want all of those. You may most likely get away with simply
these:

Now, since this can be a idea hierarchy, we additionally ask the “what’s” questions.

And, since models have a period, we ask what for the period. We do that
forwards and backwards:

Now, the 4 eons. These kind a sequence, we don’t do the entire sequence script
factor once more, since you’ve got most likely, once more, simply use these:

We additionally ask when every eon started and ended, forwards and backwards:

Instance: Rational Numbers

Let’s commit this to spaced repetition:

The set of rational numbers, denoted $mathbb{Q}$, is the set of fractions with
integer numerator and denominator, the place the denominator is non-zero.

Formally:

[mathbb{Q} = left{, frac{p}{q} ,, middle| ,, p, q in Z land q neq 0 ,right}]

The $mathbb{Q}$ stands for quotient.

See Also

Attempting to make sense of why Otis exploded en path to Acapulco this week – The Eyewall

Let’s visualize the idea graph as we construct up the flashcards. We begin with
the central node, the idea of the rational numbers:

Then we add a notation node, linked by two ahead and backwards questions:

Formal in addition to casual definitions:

And a ultimate notice on notation: what the $mathbb{Q}$ stands for:

Instance: Common Expressions

That is an instance about asking questions in two methods.

These playing cards go from an idea to a regex:

Along with the above, add playing cards that go from the regex to the idea:

Instance: Voltage

That is an instance of asking questions in several methods

The concept right here is:

1. We first ask for the definition of voltage by way of each electrical
   potential and work.
2. We additionally ask what’s the time period for every definition.

Which supplies us the next flashcards:

Instance: Isomers

That is pretty easy: we now have to be taught a hierarchy of
definitions. We’ll divide this into two duties:

1. First, definitions. Ask questions from the time period to the definition and from
   the definition to the time period.
2. Second, hierarchy: ask about subtypes and supertypes.

So let’s start with the definitions. First we ask the questions within the ahead
path:

And now the definitions, within the backward path:

We left some data out, to maintain the playing cards atomic, now we now have to ask
inquiries to recall that data:

Now we transfer on to the hierarchy, which connects these ideas. We first ask the
questions within the downward path, from dad or mum to little one:

And now within the upward path:

And, lastly, the examples:

Query	Reply
What sort of isomer is that this?	A cis isomer.
What sort of isomer is that this?	A trans isomer.

Instance: Months of the Yr

Suppose you need to memorize:

The index-to-element flashcards:

The element-to-index flashcards:

The successor flashcards:

And the predecessor flashcards:

2## Instance: Powers of Two {#powers}

Let’s memorize the primary sixteen powers of two:

The ahead playing cards ask for the ability:

Whereas the backwards playing cards ask for the exponent from the ability:

Lastly, I’ve a take a look at card that asks me to recall your complete sequence so as.

Instance: Rilke

Let’s memorize this poem:

You may run this by means of the sequence script, however that appears a
bit chilly and mechanical. We’ll use the poetry script as a substitute,
which exhibits us two strains of context and asks us to finish the subsequent line. The
generated flashcards are:

And so forth. You get the sample.

A number of these guidelines can be unimaginable to use if we needed to write all of the
flashcards by hand: it will merely be too tiresome. Happily we now have
automation.

I put up the scripts I take advantage of in this repository. These are largely based mostly on
Gwern’s scripts.

Sequence Script

The sequence.py script generates flashcards for studying a sequence, in accordance
to the ideas in Rule: Learning Sequences.

Given a file greek.txt as enter:

Greek Alphabet
Alpha
Beta
Gamma

We are able to run cat greek.txt | ./sequence.py > playing cards.csv, and this may generate the next:

Plus the cloze card:

Poetry Script

The poetry.py script generates flashcards the place you’re given two strains of a
poem and must recall the subsequent line. For an instance of utilizing this, see
here.

Most individuals use Anki. It’s open supply, has plenty of plugins, and has a
free card sync service. That is the default selection.

I take advantage of Mochi. It has a a lot nicer UI than Anki, which helps in
sustaining the behavior as a result of it’s extra nice to make use of. It additionally helps cloze
deletion for images out of the field, versus counting on a
plugin.

The one Anki function I care about that Mochi lacks is notice sorts. Anki’s notice
sorts allow you to generate a number of playing cards from the identical structured data. For
instance, you might have a “Chemical Aspect” notice sort with fields like “Title”,
“Image”, “Atomic Quantity”, and card templates like:

So from one notice (“Hafnium”, “Hf”, “72”) you routinely derive 4
flashcards. And should you edit the notice information, all of the playing cards get up to date. Mochi
lacks this function, in observe it’s not horrible, and you will get a lot of the
method there with cloze deletions.

Essentially the most cited useful resource on writing flashcards is a basic 1999 article by
Piotr Woźniak, creator of SuperMemo. The article is Effective
learning: twenty rules of formulating knowledge and I endorse most of
it. Let me reiterate the vital components:

1. Perceive earlier than memorizing: the ideas must be clear in your head
   earlier than you attempt to commit them to reminiscence. “Readability” is a fuzzy factor, however what
   I do is dig, increase, make clear till I really feel comfy formulating information.
2. Playing cards ought to be atomic, and will consult with the smallest potential
   conceptual models.
3. Keep away from attempting to memorize lengthy sequences.
4. Keep away from attempting to memorize massive unordered units of issues.
5. Maintain the wording easy.
6. Redundancy is nice. Do repeat your self!

I hope that you will see that these guidelines and examples helpful. Now go choose up a
textbook and be taught one thing helpful.