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Bringing an item back after growing gaps inside one sitting: double after a success, step back after a miss, and keep a card in play until it has come back more than once.
Paper packet. Every task here also exists on screen, where it is checked automatically; answers written on paper are not assessed by Nydus. When you are back at a device, enter your answers there.
You will run a card through a ladder of growing gaps, step back one rung after a miss, decide when a card retires, and see why one big deck spaces every card.
You have left clean gaps, used and faded cues, handled misses and rebuilt orders. This lesson puts them into one routine that runs inside a single sitting: each item is retrieved again after a longer gap when it comes back, and a shorter one when it does not.
| Term | What it means |
|---|---|
| Rung | One try at one item after one gap. |
| Growing gaps | Gaps that double after each success: 2 cards, then 4, then 8. |
| Stepping back | After a miss, using the last gap that worked for the next try. |
| Spaced practice | Tries at the same item separated by other work, as opposed to massed practice, which is the same item again and again in a row. |
| Retire | Take a card out of the deck for today, once it has come back right enough times after gaps. |
The forgetting curve drops fastest early, and a successful retrieval changes what happens next. So the most useful time to retrieve an item again is not straight away, when it is still in mind, but after a gap, when it has started to fade and the retrieval has to do some work.
Inside one sitting, that becomes a ladder. Retrieve the item; if it comes back, the next gap doubles: after 2 other cards, then 4, then 8. If it does not come back, show the answer, say it once with it covered, and step back to the last gap that worked. Then climb again.
A card is not finished the first time it comes back right. Keeping it in play for a few more spaced successes is where much of the lasting benefit is.
Another way: picture
Stepping stones across a creek, each a little farther from the last. You can always reach the next one, and by the end you have crossed a width you could not have jumped at once. A slip sends you back one stone, not to the bank.
Another way: steps
Jeffrey Karpicke and Henry Roediger (2008) had students learn 40 Swahili-English word pairs. In some conditions a pair was dropped from further testing as soon as it had been recalled once. A week later, students who had kept retrieving the pairs recalled about 80 percent of them; students who had dropped them from testing and only kept studying them recalled about a third. Extra studying of learned pairs added nothing; extra retrieval added a great deal.
Nate Kornell (2009) compared one big deck of flashcards with several small stacks studied one at a time. The big deck spaces every card by all the others, and it did better for about 90 percent of the learners. After the first session, though, 72 percent of them believed the small stacks had worked better: massed practice feels more fluent.
A review by Nicholas Cepeda and colleagues (2006) pooled 317 experiments and found spaced practice ahead of massed practice, with the best gap growing with how long the material has to last. How to lay those gaps across days and weeks is the business of the Study strategies course.
To check a record, read it from the top: each gap should be double the one before after a tick, and half of it after a cross. A running total, the gaps added up, tells you how long after first study each try came.
Work through a fictional case. Elena has 20 vocabulary cards for a Friday quiz and twenty minutes. Her old habit was four stacks of five, each gone through until every card was right once. This time she uses one deck of 20. When ventana comes back right, she slides it about 4 cards down; next time, 8; then it retires for the night. When cuchara is missed, she turns it, covers it, says spoon, and slides it 2 cards down, the last gap that worked. At the end, 15 cards have retired and 5 are still in play; those five start tomorrow's deck.
The sitting felt harder than the four small stacks, which matches what Kornell's learners reported. Each card simply had more of the deck between its tries.
Dropping a card after one right answer. It feels done. Karpicke and Roediger's week-later results say it is not: a card recalled once and then dropped from retrieval was far more likely to be lost.
Small stacks because they feel smoother. The smoothness comes from the card still being in mind. It is the same illusion as rereading.
Starting over after a miss. Step back one rung, not to the bottom. The earlier successes still count.
Put the card 2 cards down after its first right answer.
Try 1 ✓ → next gap 2 cards
The ladder starts short.
Double after the next success.
Try 2 ✓ → next gap 4 cards
A success earns a longer gap.
Step back after a miss.
Try 3 ✗ → answer shown, said → next gap 2 cards
The last gap that worked was 2 cards.
Climb again, then retire.
Try 4 ✓ → 4 cards; try 5 ✓ → 8 cards; try 6 ✓ → retired
Three spaced successes in a row retire the card for today.
Write the gaps in order.
Gaps: 3, 6, 12
Each gap is double the last after a success.
Add each gap to the total before it.
3; 3 + 6 = 9; 9 + 12 = 21
The running total is how far the card has traveled since first study.
Read what the total says.
Third try: 21 cards after first study
Three short tries have reached a gap far longer than the first.
Double after each success.
3 → 6 → 12 cards
Two successes, two doublings.
Step back after the miss.
In a deck of flashcards, a card came back right when it was put back 2 cards later, then 4 cards later, and then was missed when it came up 8 cards later. What should happen to it next?
A card comes back right after gaps of 2 and 4 cards, then is missed at the next doubling. Complete the worked plan for its next two tries, if the first of them is right.
Show the answer and have it said once with the card covered.
Missed → answer shown, said once with the card covered
The last thing produced should be right.
Step back to the last gap that worked.
Next try after p cards
That gap was bridged before, so the next try is likely to succeed.
After a success there, double again.
The try after that: q cards
The ladder climbs again from where it was.
One rung of a ladder, for practice: study the five words, wait one minute doing something unrelated, then write back what you can. In a full sitting, each word that came back would return after a longer gap, and each missed word after a shorter one. This is practice, not a test of your memory.
Ask someone to read you the list, then cover it and write what you remember:
A fictional sitting with Spanish vocabulary cards. The rule: a card stays in the deck until it has been produced right three times, each after a gap. Records so far: *perro* ✓ ✓ ✓; *gato* ✓ ✗ ✓; *casa* ✓ ✓; *mesa* ✗ ✓ ✓ ✓. For each card, write how many spaced successes it has since its last miss, and whether it stays or retires for today.
| Successes since last miss | Stay or retire | |
|---|---|---|
| perro | ||
| gato | ||
| casa | ||
| mesa |
Run one card through a sitting. Its first gap is 2 cards. The five tries went: right, right, missed, right, right. Press the rule for each try in turn, and finish with the gap the next try should use.
This task has no paper form; do it on a device.
Nate Kornell (2009) had learners study vocabulary cards either as one big deck or as several small stacks studied one after another. A fictional student has 20 cards for a Spanish quiz. Going through them as one deck, how many other cards come between two tries at the same card? Split into 4 stacks of 5, how many?
One deck: x cards between tries. Small stacks: y.
Lesson test: one question per skill, one attempt each, no hints. Your answers are checked when you submit.
One card's record in a sitting. The first gap is 3 cards. Tries 1 and 2 were right, try 3 was missed, try 4 was right. Fill in the gap before each try from try 2 on, and the running total of cards since the card was first studied.
| Gap before it, in cards | Cards since first studied | |
|---|---|---|
| Try 2 | ||
| Try 3 | ||
| Try 4 | ||
| Try 5 |
Without looking back: what happens to a card's gap after a success, and after a miss, and why is one right answer not enough to drop it? Next: the Study strategies course turns these gaps into a schedule across days. A trial here is practice, not a test of your memory. What is kept is the list you wrote back on this device today, and it is never set beside anyone else's. You can stop at any point: closing the page is the whole of stopping, and the lesson reopens where you left it.
11. Your turn: a card's first gap is 3 cards. It is right, right, then missed. What gap comes next?, step 2
Next gap: 6 cards
Six was the last gap that worked.