Zettelkasten

Do you struggle to learn different topics or keep different subjects in your head while you are working on some project? Well, me too. I have ADHD. I have multiple interests. When I hyperfocus on one of my interests, time flies. But usually, I need to learn different subjects and make them work together on a project. And I bet you need that, too. How can you solve it? One technique I use for studying different topics and making them work together is the Zettelkasten method. And you will learn how to leverage it to improve your learning.

If you search the internet for the term, you will find many references, most of them using some digital tool, the most popular being Obsidian. You’ll likely find a tutorial with a complex workflow with many plugins, folder structures, tags, etc. However, here we will discuss the analogue way, the way it started with Niklas Luhmann.

Clearing a misconception

If you do some research, you may find that Zettelkasten started with Niklas Luhmann, a German sociologist. That’s not correct, many authors and researchers have used some variation of the system before. Antonin Sertillanges, Walter Benjamin, Roland Barthes and others have used a similar system ¹. However, Luhmann was so prolific in his writing and built a system with ninety thousand cards that many associate Zettelkasten with him. Nevertheless, the purpose of this text is to show an easy implementation of the system, not to teach history. Zettelkasten is just the German word for slipbox, nothing more. Nobody claimed to invent a method with this name. Still, given Luhmann was German, we conventionally use Zettelkasten to refer to his note-taking method and organisation.

The method

This will be a brief explanation. If you want to go deeper, check the book Antinet Zettelkasten by Scott Scheper or Kathleen Spracklen YouTube channel.

You need cards in the size you find best. Kathleen and Scott use 4"x6", which is also reasonably easy to find in Brazil (I’m Brazilian). I use the A6 format, which is almost the same size, just a few millimetres difference. Now, I have a bunch of A6 cards, but when I started, I used to cut A4 sheets into A6. This is the wonder of the ISO 216 standard: A4 folded in half gives A5, and A5 folded in half gives A6.

You will create three sets of cards: index, bibliography, and main.

Bibliography cards

When reading a book, an article, or watching an educational video, put the bibliographic reference on the front of the card. When you find an interesting passage, you can note a location reference and a brief comment about the passage on the back. For example, “p114 interesting how the author defends such a viewpoint, it is the opposite of what I expected” or, if it’s a video, you can note the time reference “13:30 An example of how to make a connection with other notes in the digital model.” Moreover, you can use this card as a bookmark while reading the book, and it will help you always be prepared to take notes. If the card fills up, take another paper. You will have some quick notes based on your reading.

Store these cards alphabetically by the author’s name. I like to keep dividers with alphabet letters for easy access.

You may find other texts or videos using the name literature notes. If I’m not mistaken, this terminology is from Sönke Ahrens, Luhmann didn’t use it.

Main cards

Now, let’s move to the main set. After reading, reflect on those bibliographic notes and write your thoughts on the subject in your own words on a blank card. It doesn’t need to be one-to-one with the bibliographic notes. Just because you commented on 20 passages from a book, it doesn’t mean you will create 20 notes. Reflect on what you read and create one or more notes in your own words. Here, anything can happen. You can discuss the author’s ideas, but with your own words: “So-and-so addresses the idea that blah blah blah and argues blah blah blah.” In this case, I also recommend referencing the bibliographic card because you can cite the sources correctly if you want to write an article. Or you may have read several authors on a topic and noted your ideas: “The importance of programming in Python is because we can do this, that, and the other. (…)”. Or you might have an original idea. Most videos and texts you find out there about Zettelkasten will say that you should write only in your own words. But Luhmann also copied quotes. Anyway, they are your notes, so do what you want. I recommend clarifying that you copied a quote or wrote something from your head. Beware of plagiarism.

After creating a card in the main set, assign a number. It will be the address. Here, you can invent anything. Later, when you write another card, you assign related or unrelated numbers, depending on the subject. This is where many people get confused or invent something very complicated. But it doesn’t need to be complicated. Let’s say you wrote about Python and decided to give it the number 100. Then, you wrote about graphs in Python. It seems related to Python, and it could be number 110. Later, you wrote about dashboards. Dashboards are related to graphs, and they could be within this category. You could call it 110.1. Then, you write something else about dashboards, for example. It would be 110.2. Continued something about dashboards, it goes to 110.3. And you create more levels. Let’s say you decided to talk about a specific dashboard tool, but the topic of dashboards was 110.1. You could talk about this tool and assign 110.1.1.

Let’s say you wrote about data analysis and assigned the number 200. Within data analysis, you find it important to talk about dashboards. But you’ve already used dashboards in 110.1. That’s okay, you don’t need to number it again. You note on your card something like “see also dashboards 110.” That way, you don’t need to move cards around if you think they could be better addressed under a new category and don’t change the address.

The index

Finally, the index. For some main cards, you can add an entry to the index. For example, you write “Python 100” under the letter P. Under the letter D, “Dashboards 110.1”. You wrote about dashboards in 110.2 and 110.3, but you don’t need to put all cards in the index, just the main ones. Over time, when you need to consult a subject, you go to the index. And as similar subjects will be numerically close, you easily find other related cards.

It seems complicated, but you quickly get the hang of it when you start doing it.

An important note

When reading about Zettelkasten online, you may have the impression that it’s easy to take notes and magically produce hundreds of articles later may rearranging your notes. There’s no magic. You need to put in the work. You need to think to write good notes. You need to have clear ideas. And you need to put the effort to organise your thoughts in a coherent manner when writing an article. However, it’s easier doing that from your notes than from a blank page.

Conclusion

A question that might have crossed your mind: why go through all this trouble with cards when it would be simpler in software and still has the search function? First, preference. Some people like to study with pen and paper. The second is retention. When we write on paper, retention is higher than when we type. The important thing is to find a method that works for you.

A good method should suit your preferences and enhance your learning. Some find studying with physical cards enjoyable and beneficial for memory recall. This approach allows you to engage with the material deeper by summarising and reflecting on your learning. While digital tools offer convenience, the tactile experience of committing information to paper can improve your understanding and retention. Choose a method that aligns with your learning style and goals.

Photo by Niklas Luhmann Archiv licensed under Creative Commons: CC-BY-NC-SA-4.0

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