Remembering R – Using Spaced Repetition to finally write code fluently

Installing Anki And Extensions

To install Anki, go to https://apps.ankiweb.net/ and click on “Download”. Choose Anki 2.1 and follow the installation instructions.
When you open up Anki, this is what you should see:

Figure 1: What you should see when you open Anki the first time

(I am using the macOS version of Anki, so yours will look slightly different if you’re on Windows or Linux, but it will work the same.)

With Anki installed, you will need to install two other things, two Anki Add-ons:

1. Mini Format Pack
2. Syntax Highlighting for Code

To install Add-ons, go to “Tools” in the Anki Menu and then go to the “Add-ons” menu:

In the window that opens, click on “Get Add-ons”:

In this window, you will need to enter the numeric IDs of the addons you want to install. To get these IDs you either click on “Browse Add-ons”, which will take you here, and then search manually for the two extensions we want to install, or you follow these two links which will take you to the Add-on pages directly:

• Mini Format Pack
• Syntax Highlighting for Code

On these pages, you will find a section “Download” with a number code that looks something like the picture on the left, which you will need to paste into the “Code” field of the “Get Add-on” window:

Click on “OK” and repeat the process to install the second Add-on.
Once you have both Add-ons installed, you’ll need to tweak the settings in two places. First, in the Add-ons overview window, select the “Syntax Highlighting for Code” Add-on and click the “Config” button:

In the window that opens, adjust the section that reads “limitToLangs”. Depending on which programming languages you want to learn, provide their names as a comma-separated list inside the brackets, with each language enclosed in quotes. Note: For R to be recognized, the language you have to give is actually S for historical reasons. So you would have something like:

"limitToLangs": [
        "S",
        "Python",
        "Bash"
    ],

if you wanted to learn R, Python and how to use the command line. Adjust the “style” section to read "style": "manni" and click on “OK”.

Back in the “Tools” menu, find the “Syntax Highlighting Options” menu and adjust the setting there to have “Line Numbers” unchecked, “Center Code Fragments” unchecked, “Use CSS classes” checked and “Default to last language used per deck” checked, like this:

You have now installed everything to start learning R and memorizing its syntax with Anki. Now we can move on to the nitty gritty.

Example - How to Create New Flashcards for R in Anki

I’ve created a sample collection of cards, including a custom card type for you to reuse with your own cards, that you can download here. If you’d rather not download the example deck but want to set up Anki completely yourself, check out this section where I show you how to configure Anki cards yourself.

Once you have downloaded the deck, go to File > Import and then select the Empiria.io – Demo Deck.apkg file you got out of the .zip-File you downloaded. Anki should now look like this:

To start making cards, click on “Create Deck” (more on decks and cards here) and give it a name. Then click on that deck and then click on “Add”. You’ll see something like this:

From the drop-down menu that says Basic, select the note type Programming - Typing:

Now let’s make two Anki cards. In the first one we are going to start really early and train how to assign a data frame, and in the second one we are jumping into the Tidyverse to learn how to make a new column.

I’m going to do this in a list of steps, which you can simply repeat for every card you make on your own.

1. Think of a concrete task that you want to practice
   Write this task into the “Task” field of your new Card:
   “Assign the number 10 to the variable x”
   
2. Write the code for the example, either in RStudio or any other text editor
   

x <- 10

3. Make sure “S” is selected in the box next to the Lightning symbol

4. Copy the code
   
5. Paste with Alt + S
   Select the “Code” field with your cursor and press Option/Alt + S. This will add your code, formatted correctly. Do not use your normal paste-command, use Option/Alt - S.

6. Select portion you want to memorize Select the code you want to memorize, which here is everything. Make sure to select no whitespace at the beginning or the end, this might mess up formatting.

7. Press Shift-Cmd-C to turn into a cloze Press Shift-Cmd-C to turn the selected code into a cloze. When you want to create multiple clozes for one piece of code, repeat this for the other parts. Note that clozes can’t overlap.

8. If there is anything going on that you want to explain, type this explanation into the “Explain” field.
9. Write “R” into the “Category” field (unless it’s already in there)
10. Click on “Cards” to see a preview and check if everything is looking as expected.

11. Click on add. Done.

You now have your first flashcard for learning R, good.

Let’s repeat that with another example, with slightly more complex code.

1. Think of a concrete task that you want to practice
   Write this task into the “Task” field of your new Card:
   “Take the data frame df and use the pipe to create a new column called sum that is calculated from the columns a and b.”
   
2. Write the code for the example, either in RStudio or any other text editor
   

with_sum = df %>% mutate(sum = a + b)

3. Make sure “S” is selected in the box next to the Lightning symbol
   
4. Copy the code
   
5. Paste with Alt-S Select the “Code” field with your cursor and press Alt-S. This will add your code, formatted correctly. Do not use your normal paste-command, use Alt-S.
6. Select portion you want to memorize
   Select the code you want to memorize. Here, select %>% and do step 7, then select mutate and do step 7, and finally select sum = a + b and do step 7. Make sure to select no whitespace at the beginning or the end, this might mess up formatting.
   
7. Press Shift-Cmd-C to turn into a cloze
   Press Shift-Cmd-C to turn the selected code into a cloze. When you want to create multiple clozes for one piece of code, repeat this for the other parts. Note that clozes can’t overlap.
   
8. If there is anything going on that you want to explain, type this explanation into the “Explain” field.
   
9. Write “R” into the “Category” field (unless it’s already in there)
   
10. Click on “Cards” to see a preview and check if everything is looking as expected.
    
11. Click on add. Done.

Setting Up Flash Cards in Anki

Anki is an extremely powerful tool for learning just about anything because it allows you to create custom formatted flashcards that look and behave exactly like you want them to behave. However, with great power comes great complexity: setting up Anki to your liking can quickly become a hobby in itself and beginners in particular are often easily overwhelmed when starting to use Anki. In the following, I’ll show you how to create the ideal card type for learning R and any other programming language. If this seems intimidating to you or you just want to get on with your life and learn R already (very sensible, get after it!), no worries, I’ve created a sample collection of cards, including a custom card type for you to reuse with your own cards, that you can download here and once you’ve done that you can skip to making your cards.

If you have time on your hands and want to learn how to optimize Anki: let’s go.

Back in the main Anki window, click on “Add”. This will open a new window, in which you will enter the information for your cards. Here’s a quick overview:

1. Is the card type (here: “Basic”), which determines which fields a card has and how it behaves. We will make a new one that is taylored to our needs.
2. This is the Deck, the pile of cards we want to add our new cards to. This can stay the way it is.
3. Here we customize which fields our card has. Currently we have the “Front” and “Back” fields to which we can add information that Anki uses to create the cards.
4. This lets us edit the cards that Anki shows us, such as how they look and how they behave.
5. Here we select for which programming language we want to have syntax highlighting.
6. This field will let us add cloze deletions, the power feature for learning programming and your new secret weapon. You’ll learn more about how exactly this works in the next section.

To make our own custom cards to learn R, we first need to add and rename some of the fields. Because we want to leave the type “Basic” intact, we will make a copy of the type and then edit this copy. To do so, click on Type: “Basic”, then on “Manage”, “Add”, select “Clone: Basic”, confirm by clicking “OK” and then give the new card type you want to create a name. I chose “Programming - Typing” as a name. Confirm by clicking “OK”, close the pop-up windows and select your new note type:

Now, click on “Fields…” and then rename “Front” to “Task” and “Back” to “Code”:

Then, click on “Add” and add two new fields. One called “Explanation” and one called “Category”. For the “Category” field, make sure to select “remember last input”.

Then confirm by clicking “Close”. Then click on the “Cards” button, which will take you to a window looking something like this:

• Front Template (1) shows you the HTML of the front side of the card
  
• Styling (2) shows you the CSS code for the highlighting
  
• Back Template (3) Shows you the HTML for the back side of the card

In the front and back template you see things like {{Task}}, which signify the fields you created. You can reference any field of your card in your template by enclosing it in {{}}.

To set your new card type up for learning R (or any programming language), copy the following code into the Front Template:

Copy the following code into the Front Template:

<b>{{Category}}:</b><br>
<hr>
{{Task}}<br>

<div class='code'>
{{cloze:Code}}
</div>
 
{{type:cloze:Code}}

If you know HTML this code is obvious to you, if you don’t know HTML do not worry, you do not need to. Just make sure you have copied everything into the field and then copy the following code into the Back Template:

<b>{{Category}}</b><br>
<hr>

{{Task}}<br>

<div class='code'>
{{cloze:Code}}</div><br>
<div style='text-align: center;'>{{type:cloze:Code}}</div>
<br>
<div style='font-family: Helvetica; font-size: 20px;'>{{Explanation}}</div>

The code for the Styling field is very long, so here’s a link to the styling text file. Simply copy and paste its content into the appropriate field. This will ensure that you have proper highlighting of the different variables and functions when Anki shows you code.

Once you have done all that, you are now set to make flash cards.

Decks, Cards, and Settings

Let’s talk a bit about some very basic terms in Anki parlance and then configure Anki to maximize what you get out of your time using it. I know that this seems incredibly complex, and it is. If it’s too annoying to you, you can download a sample collection of cards, including a custom card type for you to reuse with your own cards and once you’ve done that you can go make your own cards and just start to learn. It’s more important that you start using Anki as soon as possible than read through everything I’ve written.

In Anki, a deck is a stack of flashcards that belong together. When you opened up Anki for the first time, you had one deck already, called Default. You are not limited to this one deck, you can create multiple (many) decks for different purposes, so one for R, one for learning Spanish and one for learning Geography. But it’s generally not recommended to have too many decks, and I would indeed recommend that you stick with one single deck for the time being, even if you use Anki for more than learning R. That’s because doing your reviews becomes a lot less monotonous and boring if you are getting asked about more than just a single topic, which helps you stick with doing your Ankis and therefore helps you learn better.

Anki will show you the cards you create according to how well you remembered them the last time. To do that, Anki divides your cards into three stages: cards you are just learning, cards you have learned and are reviewing and cards you had learned but recently didn’t remember correctly. I’m not going to go into detail here about how Ankis algorithm works exactly, just so much: every time you are shown a card, you tell Anki whether you know the answer and if yes how well.

For example, in this card I can answer whether I didn’t know it at all, if it was hard to remember, I remembered it or if it was really easy to remember. Depending on how I answer, the interval when I will next see the card changes: either in 30 minutes, 2 days, 3 days or 4 days. How long these steps are differes depending on which stage of learning your card is in. Ankis default settings for the three stages (learning, review, lapsed) are not entirely optimal, so we are going to tweak them. Remember that you can always return these settings to the default if you are not happy with them or tweak them to your own liking. This is just a best practice to get you started.

On your main Anki screen, click on the Gear icon next to the Default deck and select Options. You are now in the options tab that edits the behavior for new cards, cards you are just learning. Change the settings to the following:

In the Learning Tab:

• Steps (in Minutes): 10 1440 8640
  Anki gives you multiple steps to learn a card. Here, we set the steps to 10 minutes, one day (1440 minutes) and 6 days. So if you know a card once, you will see it again in 10 minutes, if you know it again in one day and if you then know it again in six days.
  
• Order: Show new cards in random order This way you are not cheating yourself because you are helped in remembering the content of a card because you know its context in the deck, like the card that came before.
  
• New cards per day:
  You can adjust this to your liking. I personally have it set to 30. Remember that the higher you set this, the more reviews you will have tomorrow and the days after in addition to the new cards you are seeing for the first time. The Anki Manual states that with a limit of 20 you’ll on average have to review 200 cards per day. Act accordingly.
  
• Graduating Interval: 15 days
  This means that if you know a card after having it not seen for 15 days it will move from the “learning” stage to the “review” stage. The purpose of increasing this so much is so that your have truly adequate time for learning a card before Anki penalizes you for forgetting it once.
  
• Easy Interval: 20 days
  If you press easy when reviewing a card, Anki immediately moves it to the Review stage and skips any learning steps.
  
• check the box at Bury related cards Another option that helps you learn better by removing the “context” of a card.

In the Reviews Tab:

• Maximum reviews per day: 9999 You want to do all reviews that Anki tells you to do, because otherwise you are messing up the algorithm. The best way to limit how many reviews you have to do per day is to only learn a low number of new cards per day and to do your Ankis literally every day so that you never have a backlog of reviews to come back to.
  
• check the box at Bury related reviews
  Again, remove context to remember you cards better on their own.

In the Lapses Tab:

• Steps (in Minutes): 30 1440
  The steps for re-learning cards where you lapsed once.
  
• New Interval: 20%
  How soon after remembering a lapsed card you want to see it again? By default Anki has 0, effectively turning a lapsed card into a totally new card. But after once forgetting a card you knew for a year, do you really need to see it tomorrow, the day after and a hundred times more? No, so 20% of the previous interval is good.

If you have any feedback or question, do not hesitate to email me! You can also use the anonymous feedback form if you prefer.