What do these flashcard options do?

[Bendy-Ren]

In New Test —> More Settings —> Scoring, what do the two options below do?

If review early— don’t change, change normally, scale exponentially, scale linearly

If review late— change normally, scale logarithmically, scale linearly

I mean, I know (vaguely) what the words mean... but what is the difference between them in practical terms, and why would I choose one over the other?

Edit: Some more information for my specific use case, that might help someone advise me:

I have a pretty massive flashcard database, and I often accumulate hundreds of overdue cards if I don't test for a few days. I want a setting that will make catching-up easier, if possible.

 

[mikelove]

Review early: this determines how much your interval increase is reduced if you review a card ahead of schedule. Normally means that you get the same increase you'd get if you reviewed on time, exponentially means that it takes whatever fraction of the normal interval you waited and squares it, then multiples that by the default interval increase to give you your interval increase; for example, if you reviewed a card at half the expected interval, you'd only get (1/2 * 1/2 =) 1/4 the normal interval increase. Linearly skips the squaring and in the above example would just give you half the interval increase for half the interval.

Review late: determines how much your interval increase is increased if you review a card behind schedule. Normally again means that you get the same increase you'd get if you reviewed on time. Logarithmically means that multiply that increase by the extra interval, then take the square root of the extra and give you that as as bonus; for example, if you reviewed at 150% of the scheduled interval and the normal increase would be 8 days, we take 50% of that (4 days), take the square root of it (2 days), then add that to the default 8 days as the bonus. Linearly means there's no square root, if you review at 150% of the scheduled interval you get 150% of the interval increase.

So as far as catching up, you'd probably want to leave "review early" as is and use the most aggressive "scale linearly" option for "review late" - that will mean the longest waits before cards come up again.