Ask HN: How do you synthesize books that you read?

I only read books on kindle, and i use kindle highlights. After I finish a book, I usually wait about 1 month or so, then I download the kindle highlights and turn them in to Anki flash cards and review them every day.

The type of cards i make are

1. vocab i didnt know 2. interesting paragraphs 3. other examples using cloze

SMS works, and this method definitely works, but it's a lot of work. One really good thing that comes out of this is even if I cant recall exactly what I wanted, I always can remember the book it came from and the kindle highlights give me the page number to go read it again.

1. Read the book, taking notes on a wiki page dedicated to that specific book (I self-host a Mediawiki install for stuff like this). In this first pass, I tend to take really detailed notes, at times practically transcribing large portions of the text.

2. Re-read these notes a couple of times. Add hyperlinks to related material, read related material, etc. I may also edit the notes to reflect better understanding, or just to fix typos and suchlike.

3. Start a new page called " Synthesis". In here I rewrite my notes, but very specifically not direct transcription. I write what I think about the topic, based on my reading(s) above.

4. Re-read the notes from (3) above every now and then. Possibly editing for clarification or whatever as I go.

5. At some point I may do a synthesis page that synthesizes my thoughts from multiple related books on a similar theme or topic.

So yeah, that's a lot of work and it doesn't scale to being done for every book I read, not even close. But it's what I do when I really want to focus in on something specific and really do an intensive deep-dive.

The other thing I will sometimes do is make an Anki deck from the book I'm reading, and then review those periodically.

Outside of that: if it's a programming book, I usually code up the examples / exercises, and then depending on what it is I may extend myself to push and do things beyond the provided examples / exercises (like a book on a new programming language I'm just learning, for example). For a book on something related to electronics, I may well assemble and test circuits on a breadboard, take measurements with the oscilloscope / spectrum analyzer / etc... And so on. What tangible artifacts come out of reading a book really depends on the book. I might even be reading a book on "Foraging for Wild Edible Plants" and the tangible outcome might be tonight's dinner. shrug

If the book is about making data-intensive applications, for instance, I'll write such an application as I work through the book, using the concepts that I'm reading about.

I'll also not worry about memorizing every bit of knowledge in the book and instead strive to remember what information is in the book so that when I need to know something specific, I know where to look.

I've found note-taking to be worthless to me, but I know that many people find it valuable.

If the book doesn't have problem sets, per se, I come up with ways of testing myself that I understood the material usually through a small side project or by revisiting something I did before and trying to rework it using the new knowledge I'm trying to gain.

I also do this for fiction. I keep journals of all the books I've read, what I was thinking about at the time, my impressions while reading it, interesting passages that stood out to me, etc. I re-read books and I write new journal entries for the second (or third, etc) reading: context and history often change how I think about, react to, or enjoy a story.

Thinking to me starts with writing.