Meetup summary

2026-05-22 - Intro to Spaced Repetition (memory) Systems

Two compelling essays by Michael Nielsen that really get at the core of why spaced repetition is magical. I’m not planning to directly cover this background and instead encourage everybody to read these:

If you’re interested on getting started on your own, I recommend starting with the official Anki docs. I’m not necessarily endorsing Anki, but its desktop client is open source and it has the widest support and most advanced features at the moment. Being open source, it is also more portable than most other systems.

For more background in the mechanics and motivation for SRS in general, as well as technical writing and justification for various modeling assumptions about memory, and an opinionated guide on use cases, I highly recommend Piotr Woźniak’s SuperMemo wiki. This is maintained by the creator of SuperMemo, which as far as I’m aware is the first digital SRS implementation (or at least the most influential early system).

Agenda:

Today won’t be a “lecture” or anything of the sort. Instead, I want to motivate the idea of a spaced repetition system.

  • What is “spaced repetition”? (This means a lot of different things to different people.)
  • Why use a spaced repetition system (SRS)?
  • The distinction between notes and cards (to borrow Anki parlance). This is an important concept to understand even if you don’t use Anki per se.
  • How I like to codify facts into my own system (essentially a hybrid between traditional SRS and Zettelkasten techniques):
    • Break down basic notions, results, and any insights that I want to capture into atomic1 notes (facts).
    • Judiciously “link” atomic cards to form an implicit personal knowledge graph (PKG).
    • Review at a pace as dictated by SRS
    • Actively refactor notes at review time as needed to enhance clarity, save time, or delete facts I no longer care to retain.
  • Walk through a (hopefully self-contained) technical paper to demonstrate how you might incorporate it into your own SRS.
  • Show some examples of my own SRS review cards and critique them.

Today will also be about setting the stage for the next meetup, where I want to highlight some shortcomings I see in the SuperMemo/Anki (and related) systems and also enhance portability and flexibility of an SRS-oriented PKG.

Notes:

We had some good discussions on SRS and memory in general. We spent more time than I anticipated on memory itself (in addition to SRS in isolation). Didn’t work through a sample paper. We’ll probably skip that next time to focus on custom SRS scheduling, but if there’s interest we can work through a paper at some future meetup.

Footnotes

  1. The notion of atomicity is clearly subjective here. More importantly, it changes over time as your embeddings of a given concept sharpen or come into relief with respect to other facts. You will very likely want to “chunk” concepts differently as you continue to incorporate new facts into your KG. ↩

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