Recently, a friend messaged after I posted one of my book notes:
“I am quite curious, do you take notes while reading the book or after you are done reading? Quite a thorough summary.”
Well, incidentally, I’ve been thinking of writing on this topic for a while now. So, here it is.
What I want to talk about is something called progressive summarization. I learnt this note-taking technique from Tiago Forte, and I’ve been using it ever since.
Now, before I describe what progressive summarization is, there is a prerequisite.
You’ll need to keep a commonplace book.
What is a commonplace book?
According to Ryan Holiday, a commonplace book is:
“… a central resource or depository for ideas, quotes, anecdotes, observations and information you come across during your life and didactic pursuits. The purpose of the book is to record and organize these gems for later use in your life, in your business, in your writing, speaking or whatever it is that you do.”
As a person whose main job is to write (and speak occasionally), the value of such a tool is obvious. I can easily extract facts, stats, quotes, etc. whenever I need it. And depending on the variety of materials I consume, I can gain access to unique ideas (or create unique ideas.)
But a commonplace book isn’t just for writers or speakers. If you’re a knowledge worker, this tool will benefit you.
You can use it for your presentations or pitches. You can use it to recall vital information that might strengthen your arguments against whoever you’re debating with. You can use it to inspire yourself when you’re stuck. Or you can use it to cross-pollinate ideas from various areas.
I’m sure you can imagine the infinite uses of a commonplace book.
Now, the key question is: how do you keep one?
Well, it doesn’t have to be complicated.
If you’re going the offline route, you could store notecards in a shoebox. Or you could use a Moleskine notebook.
If you’re going online, there are even more choices. Google Drive, OneNote, Apple Notes, Evernote, Trello, Notion, etc.
Currently, I use Notion.
I’ll have to admit I’m probably using <5% of Notion’s capabilities. But since my company uses it, I consider it somewhat familiar. Which is why I chose it.
Here’s a glimpse into how my commonplace book looks like:

This is one of the many categories I’ve created. Each item you see here is a new page I’ve created for a book, podcast, article, etc. I’ve taken notes on.
Cool?
Now, back to progressive summarization.
Progressive summarization: 5 layers
At this point, I’m going to assume you’ve set up a commonplace book, or at least have some place to store your notes.
So, what is progressive summarization?
The term “progressive” suggests that it has levels. And indeed it has. Let’s go through them.
Level 1: Your original set of notes
As you’re reading a book, you should be taking note of anything that is insightful, interesting or useful.
If you’re reading online—like on Kindle—this should be quite easy. Just highlight the parts you like.
If you’re reading physical books, you can highlight too. (That is if you own the book.) If you borrowed it from the library, or you just loathe the idea of “dirtying” your book, you can use post-it flags—which is the method I use currently.

When you’re done with the book, extract your highlights.
If you’re using Kindle, you can use Bookcision to export your highlights. If it’s a physical book, I’m sorry, you’ll have to type it out.
SIDENOTE. I’m assuming you’re using an online commonplace book, since that is what I’m using. Pen and paper is perfectly fine.
Add your highlights to your commonplace book.
Level 2: Bolding
This is the next round of summarization, where you bold the best parts of the notes you’ve imported.

Level 3: Highlighting
The third round of summarization is where you highlight your notes. This is where you’re looking for the “best of the best”.

At this point, you’d have a core set of notes that truly represents the “gold”. The next time you review this set of notes, it’ll be much easier to notice the “best of the best” insights from the book.
Level 4: Executive summary
At Level 4, you’ll take what you’ve bolded and highlighted in Level 2 and 3, and rewrite it in an executive summary at the top of the note. Restate the points in your own words.
Level 5: Remix
For the small set of notes that make it to Level 5, you add them into how you work and think. You can do that by “remixing” these notes, i.e. recreating them in a new shape or form.
This could be an article, a Twitter thread, an Instagram post, a critique, a book, song, etc. I’m sure you can come up with all sorts of ideas.
Pretty easy, right?
Here are a few more subtle points you should take note of:
1. Each level is done in a just-in-time manner.
You don’t run through Levels 1-5 at one shot. Instead, you do them opportunistically.
That means: each time you are reviewing your notes, you do the next level.
Here’s an example of what I mean.
Let’s say I just finished reading the book Weapons of Math Destruction. I’ll add all my highlights into my commonplace book (Level 1).
And that’s it. I don’t need to do anything else.
Level 2 will be completed when I next access this set of notes. For example, I might need to review them because of a blog post I’m writing. Since I’m already reviewing my highlights from the book, I’ll complete Level 2: bolding the important parts.
Then, the next time I’m reviewing it again, I’ll do Level 3: highlighting. And so on.
If you’ve noticed by now, there is a “repercussion” in using this technique.
Which is:
2. Only a very, very small set of notes will reach Level 5
That’s okay.
You only need a few very important insights for your life to change.
While the commonplace book’s goal is to store the notes you’ve taken from your readings, your true goal is to surface the “quake notes”: ideas that will shatter your current worldview and transform your life.
Instead of thinking that most of your notes “won’t make it”, celebrate the fact that you’ve discovered the few insights that will alter your life for the better.
…
Now, those are the exact steps I’ve learnt from Tiago. But I’ve done it a little differently.
For most of the books I’ve read, I’ve jumped immediately to Level 4. And I’m not doing an executive summary either. I’m writing a full book summary.
My reasons for that:
- Writing a full summary helps me digest the book better;
- Writing the summary helps me view the larger themes, trends or ideas in the book;
- Writing the summary helps me join ideas from different books;
- Writing the summary helps me form an opinion. This is invaluable for a writer. A writer cannot be afraid. He/she must stand forward and present a well-structured, well-researched argument that influences.
- Writing a summary allows me to share the notes with others;
- This allows me to share useful ideas that could potentially change someone’s life;
- This also indirectly builds my personal brand: as someone who shares great ideas. Personally, I’ve benefited from this multiple times;
- I hope that, with my summaries, I’ll encourage more people to read;
- And even if people don’t want to read, I hope they, at the very least, read my summaries and learn something new.
Those are my reasons for not following the exact process.
But you’re most likely not a writer. So, you don’t have to copy what I do. Instead, follow the process I’ve laid out above – it should be more than sufficient to improve your reading and note-taking.
@ruygiraldes
October 17, 2021 — 3:41 am
Your text about the method was very well explained. Thanks to your explanation, I won’t need to spend, paying Tiago Forte’s course to better understand the principles of the method.
For those interested in the subject, I also indicate the text of this blog:: https://jamesstuber.com/progressive-summarization-a-waste/
Si Quan Ong
December 7, 2021 — 1:36 pm
Thank you! Glad it was helpful 🙂