---
date: Friday, September 4^th^, 2026
title: Why take notes?
---

I have taken a lot of notes on research papers since I started doing
research. I want to explore why I did that, and whether I should keep
doing it.

In particular, I wrote brief summaries and reflections on many of the
papers I read when I was researching reward learning and deep learning
as a CHAI intern and Master's student. I took these notes by hand, on A5
pieces of paper and arranged them across pinboards in my office like a
detective. I now have hundreds and hundreds of these hand-written slips
archived in piles on my desk. Why did I do that?

Since then, I haven't been reading papers so voraciously (with the
exception of [titles](subscribing-to-arxiv)). I've taken notes on fewer
than one hundred papers since the start of my doctorate. There's a stack
of blank A5 slips on my desk, but my pinboard sits empty. This has
happened for a mix of reasons, but I now have an opportunity to spend
more time reading. Should I try to pick back up the habit of
note-taking? Should I make any changes?

Let's explore!

## Recollection

One plausible justification is that I take notes for the purpose of
better remembering what I read. Hypothetically, simply writing down what
I read will make me remember it for longer. Maybe physically locating
the paper on the pinboard will let me associate a physical location with
the ideas in the paper.

The problem with this theory is that, now, many years after reading
hundreds of papers with this method, I remember only a tiny fraction of
the papers I read. On the rare occasion that I flick through the
archive, there are some papers I have completely forgotten having read
until I see them. There are others that I can't remember having ever
seen at all even *after* I see them.

If I wanted a memory aid for recalling all the papers I've ever read, I
would probably be better off turning my notes into flash cards and
drilling them with a spaced repetition system like Anki or, my preferred
approach, [Bayesian spaced repetition](https://fasiha.github.io/ebisu/).
Spaced repetition is highly regarded and it served me well personally
when I was [drilling German
vocabulary](https://github.com/matomatical/memograph) on exchange. Not
that I remember the vocab now. As my Bayesian app will tell you, my
probability of recalling these items has atrophied since I stopped using
it. But there was a time when I was juggling thousands of vocab items,
which is proof that I can scale this approach to the number of papers I
expect to be reading, if I want.

Of course, I'm not sure I need or want to remember every paper I ever
read. Which brings me to the next theory.

## Reference

Maybe I take notes in order that I don't *have to* remember the papers I
have read. The notes act as a summary that I can refer back to if I
merely remember *that* I read about a paper, not exactly what was and
wasn't in it. The thing is, again after many years, I have barely used
my notes in this way.

I do *sometimes* look at the notes. For example, when I'm writing a
paper, I sometimes refer back to my notes board (or notes pile) and find
papers I had forgotten were relevant and are worth incorporating into
the story. More broadly, when I want to remember what was in a paper,
the summaries I write are a helpful starting point.

However, this theory needs to reckon with the fact that I could
potentially achieve the same outcome by keeping a list of the titles of
all the papers I read during a long research project, and consulting
that list, including consulting the papers themselves if I forgot what
was in them. Papers often have summaries, in the form of their abstract,
or I could start from someone else's summary, or ask a language model.
That would all be much faster than writing my own summaries.

## Trust

The thing is, you can't always trust what you read in papers. Authors
sometimes overstate, or understate, the relevance of their findings to
my work. Sometimes they contain claims that aren't justified at all,
because they are undermined by some subtle (or not so subtle) errors in
reasoning. So another theory is that my summaries are valuable artefacts
because I've filtered them to emphasise the parts that are relevant and
de-emphasise the parts that are irrelevant or untrue.

This is something I used to believe. Recently, I realised it's a bit
naive. I'm also an author. I also sometimes overstate or understate the
relevance of findings to my work. Over the years, I have been known to
sometimes write down claims that aren't justified at all, being
undermined by some subtle (or not so subtle) errors in reasoning.

It's not like I can afford to place zero trust in things others have
written and absolute trust in things I have written. At the same time, I
can't afford to verify everything including that I just verified
everything, that's [an infinite
loop](https://en.wikipedia.org/wiki/Sphex#Use_in_philosophy).

## Conversation

Interesting! We have encountered a conceptual separation between the
person writing the summaries (myself in the past) from the person
reading the summaries (myself in the present). By reading the notes,
it's kind of like present-me, the summary reader, is having a
conversation with past-me, the summary writer.

In ["Communicating with slip
boxes"](https://luhmann.surge.sh/communicating-with-slip-boxes), the
prolific German sociologist Niklas Luhmann explains his experience
having a sustained "conversation" with a collection of boxes of
thousands of manually-hyperlinked paper slips amassed over decades. He
reports that his *Zettelkasten* system was a fruitful conversation
partner because over time it surfaced surprising connections between
ideas encountered at different times or in seemingly different contexts.

That's all good in theory. But this isn't what has happened for me, at
least historically. As a conversation, things have been almost entirely
one-sided, with the person writing the summaries doing all of the
talking and present-me not spending much time listening. Moreover, I
haven't invested the time to laboriously interlink my paper summaries or
draw connections between disparate ideas.

## Automation

Some people take the time to build a physical Zettelkasten. Digital slip
boxes are more popular. Personal wiki software can easily automate
querying and indexing. This substantially lowers the friction of
interacting with the system, and enabling smoother conversation.

These days, one can take this much further. In some sense, language
models are the ultimate form of the *corpus loquens.* Talking with a
language model is a convoluted means of querying an extremely large body
of notes. And, at times, they can make surprising connections between
disparate ideas.

But you're not talking with a past version of *yourself* when you talk
with a language model. It's more comparable to talking with another
person. It removes the need for me to take notes on what I read---the
model can summarise the papers for me as I read them. Actually, it can
summarise them whether or not I read them.

## Creation

There may come a day when I can't contribute anything to paper summaries
over what you can get from a language model. There may come a day when
research itself is automated and I have nothing left to contribute at
all. But it is not this day.

Today, I think I could still have a contribution to make. It's a
contribution that no current language model, or even no other
researcher, would make. If that's true, I'll only be able to make that
contribution by leaning into being *me,* which includes applying my
unique perspective on ideas I encounter.

Under this view, what matters is that the notes come through me. As I
read papers, certain ideas resonate with what I have read and thought
before. I write those down as a means of letting connections surface. I
ignore other ideas that evoke nothing from me in particular. Still other
ideas sound wrong, whether immediately or in a subtle way I can't put my
finger on. I pause to think out loud about why and to try to make
progress towards a better version of the ideas myself.

Thus, my notes *aren't* just a summary of the contents of the paper.
They are more like the outcome of a collision between myself and the
paper. Taking notes is how I systematically dwell on the ideas long
enough to elicit a reaction with whatever is happening in my mind.

Ah, *that* must be it.

## Conclusion

This theory of the purpose of note-taking seems pretty compelling to me.
I'm happy to try it again now that I'm getting back into reading.

In fact, I should probably lean into it. If I'm summarising as a means
of synthesising the key ideas in my own words rather than as an accurate
reference, I don't need to worry so much about being faithful to the
source, or about being comprehensive.

I should also consider more effectively achieving the goals of the
reference and conversation theories. I can keep a log of the papers I
read without committing to write detailed notes on every one. I can
schedule deliberate reviews over the notes I write, making for a more
sustained, two-way conversation, and surfacing more connections over
time.

As for changes, I am considering going digital, but I'm torn. There are
obvious advantages, especially in the language model era. And, I already
handle my title-reading habits and literature collection digitally, so
it's within reach. But there is still something romantic about the
paper-and-pinboard approach, and it gives both a physical sense of
progress and a natural point for reviewing notes (when clearing the
board). Maybe I'll try adapting both to my newly-discovered goals, and
see what works.