#concept-pamphlet #todo: review these too, continuing on the 3 day article

fsrs combines ____ with ____ ? machine learning techniques, universal memory formulas

what is fsrs? >> Free Spaced Repetition Scheduler algorithm. It is an open source algorithm.

what is the purpose of any spaced repetition algorithm? ? To help learners efficiently form long-term memories.

How do spaced repetition intervals differ with different levels of familiarity? ? Shorter intervals are used for unfamiliar material while longer ones are used for familiar material.

What is the role of automation/algos in spaced repetition? ? They automate tracking of memory states and efficient scheduling of reviews

What is the primary limitation of the SM-0 algorithm? ? It uses a page of notes as the unit for review, making it unsuitable for tracking memory retention at a more granular level

Why did Wozniak use new materials each time he sought to establish a new review interval in his experiments? ? To ensure uniformity in the intervals of prior reviews.

What are the advantages of breaking material down into smaller parts, for the SM-2 algorithm? ? It allows the algorithm to find the right schedule for each individual piece of information.

What is a primary difference between SM-0 and SM-2 algorithm, besides the fact that SM-2 uses bite-sized QA pairs? ? SM-2 also uses Ease Factor and grades.

What’s the primary difference between SM-2 and SM-4 algorithm? ? SM-2 algorithm doesn’t account for the whole lifetime of the card. SM-4 has a matrix to represent the whole memory lifetime of a card.

In SM-4, what is the main idea, practically speaking w.r.t. reviews behind Optimal Interval matrix? ? The main idea is that if the OI matrix says to wait X days and learner actually waits X+Y days and still remembers with a high grade, then the OI value should be changed to something between X and X+Y. If the learner can remember something after waiting X+Y days and get a good score, the old OI value was probably too short! :p Rows = how easy the material is Columns = how many times you’ve seen it. This matrix is continuously updated during reviews.

stability in the DSR model >> time required for the probability of recall for a particular memory to decline from 100% to 90%

retrievability in the DSR model >> probability of recalling a specific memory at a given moment

difficulty in the DSR model >> the inherent complexity associated with a particular memory

what are the 3 components in the 3 component model of memory? >> stability, retrievability, difficulty/complexity

In spaced repetition algo,

is… ? Initial interval after the first review

In spaced repetition algo,

is… ? Stability increase (SInc). Ratio of successive intervals, from the i-th interval and the preceding (i - 1)th interval

What is this equation

? Retrievability of any given memory at time t. This accounts for spaced repetition algorithms and memory models.

What are some advantages of FSRS vs. SM-2 Anki? ?

  • 20-30% fewer reviews than with Anki’s default algo
  • better at schedulign cards with delays

What is one way you can think about a memory event in probabilistic terms? ? A memory event is a single random experiment with only 2 possible outcomes and its success probability equals retrievability

What is considered a reasonable % retention to set for SR? ? 70-97% retention

References

  1. https://github.com/open-spaced-repetition/fsrs4anki/wiki/Spaced-Repetition-Algorithm:-A-Three%E2%80%90Day-Journey-from-Novice-to-Expert