How Again, Hard, Good and Easy set your next card review

The rating is the schedule. Again, Hard, Good, and Easy are not a mood and not a score out of four. Each one writes the next time that card is due. Study Lab uses a straightforward SM-2-style rule, the same family of schedulers people already know from other flashcard apps. We are not claiming a cleverer algorithm. We are claiming you should know what the button does before you tap it.

[[chart:ld-ratings]]

First press on a new card

Switch the chart to “First rating.” The hours are exact conversions of the product rules:

• Again — 10 minutes. The card stays in learning. Ease drops by 0.2, down to a floor of 1.3.
• Hard — 60 minutes the first time. Ease drops by 0.15. You have not graduated the card.
• Good — 1 day, then 6 days on the second Good, then the interval times ease. Starting ease is 2.5, so the third Good is 15 days and the fourth is 38.
• Easy — 4 days the first time. Ease rises by 0.15. Later Easys multiply by ease and by 1.3. Four Easys in a row land near 4, 8, 29, and 111 days.

First rating on a new card

Rating	Next review
Again	10 minutes
Hard	60 minutes
Good	1 day
Easy	4 days

Why this method works

A gap that grows only after a real success is the whole trick. If you mark Easy on a card you reconstructed from the last three seconds of looking, you hide it for four days and meet it cold. If you mark Again on a card you almost had, you will see it in ten minutes, which is right — and you should still be able to say it then without the back showing.

The “Four Goods” and “Four Easys” views assume you never miss and ease starts at 2.5. A single Again in the middle resets the count. That reset is the next article.

Timed session — rate one pile

1. 1 minute. Open the due pile in Study Lab. Ignore new cards.
2. 10 minutes. Answer with the back covered. Pause before you rate.
3. The test for Easy: could you have said it if the card had appeared with no warm-up? If not, it is Good or Hard.
4. The test for Again: did you fail to produce it? Familiarity is not a pass.
5. 4 minutes. Revisit anything you marked Again. Still covered.

Pitfalls

• Using Easy as a “done” stamp at the end of a long session.
• Using Again as a punishment rather than as “show me this again before I leave.”
• Comparing your intervals with someone else’s deck. Ease moves with your ratings, so two people on the same card diverge on purpose.

Read what a miss does to the interval, then go back to the 25-minute session and rate the pile you already have.

A worked rating, so the buttons stay concrete

You meet a new card: “What does a negative index do to a power of ten?” You say “it flips the fraction” and you can write 10⁻³ = 1/1000 without looking. That is Good, not Easy, if you hesitated on the zeros. Good means one day. Tomorrow, if you still produce it, the second Good means six days. You do not press Easy to “get it out of the way.” Easy is for the card you could have answered before the prompt finished.

A second card asks for the same idea and you blank. Again. Ten minutes later it returns. If you only remember because you read the back thirty seconds ago, that is not a pass — Again once more, or Hard if you had the idea and lost a detail. The chart’s first-rating view is this decision in hours. The four-Good view is what happens if you keep passing. Most real decks are a mix, which is why ease moves.

None of these numbers is a reason to shop for a different scheduler. Anki and the apps beside it have spent years on add-ons, shared decks, and their own interval tweaks. Study Lab’s job is to get the card in, let you retrieve it as a flip, a quiz, or a blank, and send a stubborn miss back through the same ratings. The interval is a tool. The produce-the-back minute is the study.