https://gwern.net/spaced-repetition#spacing-effect

Wired (original, Wozniak?); massed vs spaced (alternative)

Downsides

• interference (relatively small) in recall - ability to remember tested items drives out ability to remember similar untested items

How long it takes to memorize?

How long it takes per one question: gwern: 1.8minute; other user: 71s — but to be conservative let’s say 5min

5 min divides trivia from useful data

So it’s worth to do it > if in future we spend more than 5min to look something up > or will lose more than 5 minutes as a result of not knowing something

Downsides of cramming

at cramming memorization the average time after memorization which one has a 50% chance of remembering the memorized item seems to be 3-5 days

So don’t use SR it if you need it sooner than 5 days

Overload at 300k?

Spaced repetition is not infinite. Wozniak estimates a maximum number of ~300,000 items can be learned.