Let me ask you a question. Given two options of learning from a book which one of the following two options you would prefer:

  • Reading a book to learn
  • Having a conversation with the book

I suspect, given a chance to do so, a large number of people will prefer having a conversation with the book. Why? Because it takes consistent effort for a long time to learn from a book. So much so that we have designated institutions in place to help people learn from complex textbooks. They usually go by the names of colleges or universities.

Let me rephrase that last bit.

Colleges and universities help learners go through difficult books.

It takes a lot of effort for a learner to complete a standard academic textbook. Learners benefit from working under the guidance of instructors and working with a supporting peer group to make progress in a book over a semester or a two.

Now the question is:

Can we innovate on difficult books, a medium that has been around for over six millennia, to allow anyone to learn from them on their own?

I believe we can, and that's precisely why we have built Primer—a learning medium that allows anyone to learn from difficult books independently.

Primer is a conversational learning medium.

To understand why Primer is a better medium for learning, let's first understand the problems associated with learning.

Three Learning Problems

There are three problems that a learning medium must solve to ensure effective learning by the learner:

  1. The Problem of Attention
    The learning medium should ensure that the learner is able to focus on what is being presented for a considerably long time
  2. The Problem of Retention
    The learning medium should ensure that the learner is able to retain or has continued access to the material presented
  3. The Problem of Reflection
    The learning medium should ensure that the learner reflects about the material from time to deepen their understanding

Let's look at how Primer approaches the three problems. You can also take a look at a comics-based guide I have written which details the same idea.

Introducing Primer: Comics #1
Primer: Your learning companion for life

The Problem of Attention

Unlike videos, which you can idly watch without registering information, Primer is conversational. And conversations by default require attention.

Primer also contains built-in quizzes such as Reorder and MCQs to keep the learner engaged.  

In Primer, the learner cannot skip ahead. To proceed, the learner must respond. This is how Primer solves the Problem of Attention.

The Problem of Retention

For a long time, finding exactly when language emerged in human civilization has been an impossible problem to solve for Palaeoanthropologists. The reason why this is so difficult is that speech leaves no fossils. Similarly, learning from video-based mediums or simply reading from textbooks leaves no "fossils" or "footprints".

You might understand the entire thing for a while. But as time goes on, like footprints on the sand, your stored knowledge starts disappearing. You can watch lots of videos on a particular subject and still end up remembering nothing at all a few months later. Therefore, many learners prefer to take notes of the lectures or highlight the textbook to help them store at least a portion of it inside their minds. And sometimes, in order to remember the information for a long-time, may even try to convert it into flashcards or employ other long-term retention methods and review them from time to time.

As you can notice, learning from video lectures or textbooks doesn't mean simply read or watch them. There are a lot of secondary activities that are required for effective learning. You have to make notes, review notes, put reminders to review them periodically, discuss with peer groups so on so forth. Andy Matuschak has written an essay that goes deeper into this particular problem.

Why books don’t work
Designing media to reflect how people think and learn

Primer makes it easier for you to retain what you have learned by integrating many of these secondary activities inside a single interface.  

Allows addition of notes and questions

You can add notes directly in the interface while learning on Primer.

You can also add questions and put them as pending. The next time, you revisit the course, you can take a look at the question and seek answers from the internet or our community forums.


As your progress in the course, key glossary terms, equations, and code samples start getting added into your course material repository.

These cards are presented to you in the form of flashcards in review mode. Apart from these automatically populated course cards, all your completed questions and notes are also converted to flashcards.

To convert your notes into flashcards, Primer employs cloze-deletion, which means hiding a specific important part of the sentence in the front side of the card, and revealing the full sentence in the back. You can specify where the cloze-deletion should take place by wrapping the phrase with square brackets([]).

Also, you don't really have to be dependent on Primer for your spaced-repetition practices. You can export all your cards as Anki Packages.

Nicky Case wrote a wonderful guide for getting acquainted with spaced repetition. You can learn more about spaced repetition in the guide below.

How To Remember Anything Forever-ish
an interactive comic on the art & science of memory

Personalized Book

When you finish reading a course, you can generate your personalized course notebook. This is a book-like document in which all your responses, exercises, notes, and questions are compiled along with the course content.

You can modify the book anytime you want to by updating notes and questions on your course. While other learning platforms are quick to offer you a certificate of completion, we like to give you a personalized book. Theoretically, you cannot complete courses on Primer. Why? Because as a medium it encapsulates real-world knowledge. You cannot learn everything, rather just enough.

On Primer, you have to think of the courses you finish reading as unfinished projects.

Something that you want to make progress in gradually over years.

Right after the course completion, your notebook contains just the bare minimum of your responses.

Your goal after completion of the course, is to fully personalize the book

This means you have to add more notes and questions. We have a rule that you need to add at least 150 notes and questions to personalize the book. Although, the number is just for your reference.  

By all means, it is an actual book with your name on it. You can even order prints from local print shops and get yourself a hardcover, after fully personalizing it of course.

Makes it easier to review

“As a single footstep will not make a path on the earth, so a single thought will not make a pathway in the mind. To make a deep physical path, we walk again and again.”

Henry David Thoreau

To personalize, you will have to revisit your unfinished project a lot of times. Next time, you visit a topic after completing it, you will find that all your responses and exercises are frozen. Also, specific important phrases are hidden, which can be revealed by hovering over them. These are inline completions.  

Retrace mode allows you to review your conversation with Primers. Using inline completions and flashcards, you can recall effectively. Your own responses act as memory breadcrumbs to help you quickly recollect.

I have written much more about the idea of memory breadcrumbs in the following comics.

Memory Breadcrumbs & Memory Trails: Comics #2
Learn how Primer helps you retain things you have learned using memory breadcrumbs.

Retention score

When you first complete a course on Primer, the course gets assigned a score. As days go, the score decreases and eventually asymptotes around 1. It is called the retention score. Retention Score is a proxy indicator of the percentage of the course content that you have retained.  Its value has no relationship with the actual amount you have retained. Think of it as a reminder tool.

If you review all the course cards after course completion, the retention score goes back up to 10.

The purpose of the Retention Score is to remind you of the fact that no matter how much confidence you feel about the topic, eventually, you are going to forget all of it. You cannot stop the retention score to decrease, but you can slow down the rate of decrease.

It is a complex equation, but the thumb rule is :

The more notes and completed questions you have, the slower the retention score decreases.    

As you can see, we have quite a list of methods to solve the Problem of Retention. Next, we will take a look at the most ignored problem: Reflection.        

The Problem of Reflection

“Reading without reflecting is like eating without digesting.”

Edmund Burke

To fully personalize your course notebook, you need to add 150 notes and questions. You might wonder, how can someone come up with so many notes and questions. The answer is question-prompt and note-taking activities.

Question prompts are templates that you can use to frame better questions.  

Note-taking activities suggest creative ways to think about the material presented.

Question Prompts and Note-taking activities are our small attempts at solving a really tough problem of Reflection.

We have finished explaining how Primer works. To experience how does a primer course feels, you can check out our newly released course on Primer: Python-1.


Python-1 is an introductory-level Python course. It is aimed at individuals with no or little prior programming experience to pick up Python. You can view the course content directly as Python-1 is released as an online book as well.

Python-1 is an introductory course towards taking the first steps in the Python Programming Language. This course is designed for learners without any prior programming experience. Those who have some programming experience under their belt and want to dig deeper into Python will also find this cour…

The average completion time of Python-1 on Primer is around 13.5 hours. The notebook generated is around 446 pages. Had Python-1 been a video-based course, the amount of time taken would have at least quadrupled ( ~ 60 hours ), and even then it would not have covered all the material we have covered in this course.

You don't have to take my words. Try learning Python on Primer and you will get what I am trying to say.

Books, Video Games, and Primer

For demonstrations and tutorials, videos might be the best medium for learning available. However, for abstract and complex topics, text-based mediums such as books are better. No matter how many lectures you saw, you will eventually need to open up a book to deepen your understanding.  

It is easier to consume videos because there is less effort involved from the learner. Sometimes, books are scary hard work. It's not surprising that many prescribed semester textbooks go unopened. No one reads academic textbooks cover to cover. (Although in most cases, it is not meant to be read that way).

Books are difficult to read because it requires learners to pay focussed attention distributed over a number of days.

University settings are excellent environments to go through difficult books. Outside the university setting, it is difficult to do the same. Primer attempts to provide an alternative to the university setting, where learners can learn difficult subjects over a long period of time. Primer does this by introducing resumability into play.

To understand the idea of resumability, let's take the example of video games. Earlier videos games didn't have the option to save checkpoints. If your character dies in the game, you will have to respawn at the very beginning. The gameplay duration was limited to the skill of the player say, few minutes. Today the games have the option to save checkpoints and now the gameplay sometimes exceeds 100 hours.

The point is when you learn from videos or books, it is often like playing a game with no save point. Why? Because you are eventually going to forget and the next time you will feel like you are starting from zero. What Primer does is help you create a set of memory breadcrumbs that enable you to a) recover what you have learned faster and b) resume from then onwards. You can quit the course midway (which most of you reading this will eventually do) and return after a year or so to find your notes, questions, and responses helping you to recover what you have learned.    

Simply put, Primer is better book than a better MOOC

The downside of Primer is that the current formats of books can not be converted directly to Primer. We have to write them ourselves. We intend to write a series of courses on Primer, completing which will be equivalent to a university-level degree.

Let's look at what we are going to learn using Primer.  

Ars Longa, Vita Brevis

There is a short story by Scott Alexander called Ars Longa, Vita Brevis. You can take a look at the story here.

Ars Longa, Vita Brevis
The Alchemist asked if I wanted a drink. I did, but no amount of staring could make my eyes settle on the color of the liquid in the flask. And the gold the alchemists paid the taxmen smelled funny…

The story describes a group of people whose only job is to condense knowledge for the future generation. They are called redactors. I prefer to call them simplifiers. Their purpose is to simplify collective human knowledge. Here is an excerpt from the story about the same:

An excerpt from Ars Longa, Vita Brevis

Primerlabs aims to be a guild of redactors whose only job is to continually simplify the world's knowledge and make it accessible to everyone. Primer courses are iterative, meaning they will become better over time. We are not here to help you get a job, or certification or help you signal employability, but to simplify an increasingly complex world for you to understand.

For an ambitious goal, we are going to start with only six subjects. And as of today, we are going to start with just one: Computer Science.  

Primer CS Degree

We are announcing pre-orders for our upcoming release of the first collection of courses: Primer Computer Science(CS) Degree. Primer CS Degree is a set of 46 courses completing which will be equivalent to completing an undergraduate degree in Computer Science. Note that, we are not accredited, so completing all the courses won't give you any credentials.

The Primer Degree is designed for those who want to learn computer science but lack resources time or money. Learning to Program will constitute only a small part of the course. You are not required to know how to program beforehand.  

The courses will start getting released from Nov 2021 and we are quite hopeful that we will be able to deliver all the courses by Dec 2022. All the courses in the Primer CS Degree will be available as online books for free.

At the beginning of this post, I asked you a question. This is what I actually meant.

Each of the courses on Primer gives you a choice:

Whether to read the online book or have a conversation with Primer?

I know what my answer will be each time.

And if you do too, then do consider making a pre-order for Primer CS Degree.

We are taking pre-orders to expand our team and scale the rate of releasing courses. With high pre-orders, we can significantly accelerate the course creations and maybe deliver early.  

Our website is littered with the question:

What if, books could talk?

Our hope is, it will allow anyone to learn difficult things on their own and help make humans a multi-specialized species.