Personal Knowledge Management (PKM)
The term 'Personal Knowledge Management' (PKM) has perhaps been around since at least 1999 but I didn't come across it until 2020 or so. I believe this is because it is an under-explored space and status quo has carried practitioners sufficiently until recently. As such, numerous note-taking solutions have been popping up in recent years.
For me, Personal Knowledge Management (PKM) is how I go about taking notes and making them useful. It includes the tools to take notes, organize, and store them, and also the process to do something useful with them.
The tools and workflows of PKM takes different forms. This could be writing notes in a Moleskin notebook and reviewing the day's notes each evening. It may also or instead mean making digital flashcards and practicing them daily.
Its not unique to PKM that the tools sometimes get confused with the frameworks or workflows.
💡 See Using Obsidian for PKM for my own approach to Personal Knowledge Management workflows and the tools that support them.
There are several methods of varying levels of formality and structure to practice PKM that I've come across over the years, and most tend to be tools that are opinionated about the process you use with them and sometimes the opposite: the structure is provided but claims to be tool agnostic.
Building a Second Brain
I'm a little familiar with Tiago Fotre and his work Building a Second Brain (BASB). He deploys the 'PARA' (Projects; Areas; Resources; Archives) organizational method  and prescribes some methods for note ingestion and review.
Another not uncommon PKM method is Zettelkasten, which is a different system for how one collects, organizes, and processes information to make it useful. Not entirely dissimilar from a card catalogue of libraries in centuries past, the premise is to record very discrete pieces of information about a topic and stitch them together in useful ways. I find the concept of this method tedious and inflexible. It felt like a method more suitable for a database than for PKM.
I've used a breadth of tools since even before I had heard of PKM. I tried Microsoft OneNote back in 2007. I've also had several false starts with Evernote, one attempt with Google Keep, and a handful of different markdown editors. As of 2023-02-28 I use Obsidian.md, and the occasional Moleskin notebook.
💡 You can see many of the tools in my stack on my Uses page.
There are more tools for note-taking than there are methods for processing them into knowledge, some are prescriptive in how they should be used, others are more flexible to adapting to your own approach. Some tools are strictly offline and analog, others are strictly digital and online only and some are a hybrid. Wikipedia maintains a reasonable list of note taking apps.
Per PKM - Wikipedia Frand, Jason; Hixon, Carol (1999), "Personal Knowledge Management : Who, What, Why, When, Where, How?", Working Paper, UCLA Anderson School of Management, archived from the original on 16 May 2007, retrieved 17 February 2008 ↩︎
Per Forte Labs - The Para Method Forte, Tiago (2023); retrieved 2023-03-02 ↩︎