Don’t file you notes by author or research subject. You have to search your notes and figure out where the note should belong instead.

If you are reading about ideas in a book and file notes on those ideas within that book, it is harder to find them later. If you’re trying to find that thought, you need to first figure out what book you heard it in first.

If you file notes by book like this, your notes are likely not atomic either. Books rarely have just a single concept worth recording (unless they’re bad self help books that should have been a Tweet instead. Why are so many nonfiction books just packed with filler?)

It takes more work to file by concept. You have to search your notes and file them in a useful place. This has a few benefits though: