The guide
The J method, explained
The J method is a form of spaced repetition: reopening a course at widening intervals, counting the days (the "J"s — jour is French for day) from the one you learned it. One date in, seven dates out.
The why
The forgetting curve
Since Ebbinghaus (1885) we have known that forgetting is fast at first, then slows down: a few days after a class, only a fraction remains — unless you reopen it at the right moment. Every well-placed review flattens the forgetting curve, and the next one can wait longer.
That is the spacing effect: for the same amount of work, spaced reviews retain more than crammed ones. Add the testing effect — asking yourself questions retains more than rereading. Two of the best-documented learning techniques: Cepeda et al. (2006), Roediger & Karpicke (2006), Dunlosky et al. (2013).
The J method turns both effects into a study schedule: the widening intervals follow the curve, and every appointment is a chance to test yourself.
The scale
J1 to J90, on a real example
A class learned on Monday 5 October (its J0) gets seven reviews:
- J1 — Tuesday 6 October: the next day, when forgetting is fastest.
- J3 — Thursday 8 October
- J7 — Monday 12 October: one week, the most important milestone.
- J14 — Monday 19 October
- J30 — Wednesday 4 November
- J60 — Friday 4 December
- J90 — Sunday 3 January: the course is yours for the long run.
Nothing is sacred about the exact values; it is the growth of the gaps that does the work. An exam entered into the calendar truncates the series: there is no point reviewing after it.
By hand
Applying it with a plain diary
The method fits on paper: for every new class, write the seven dates in your diary. On the day, reopen the material — handout, notes, flashcard deck — and test yourself instead of rereading: questions in the margin, a diagram redrawn from memory, an outline recited.
Twenty to forty-five minutes is usually enough, and less and less as the milestones move apart.
The limits
Where paper breaks
The arithmetic is simple; keeping it up is not. Ten courses in parallel means seventy interleaved dates. One week of flu, and the diary shows a pile of overdue reviews nothing knows how to group. One exam moved forward, and a whole series must be redrawn.
None of that takes willpower — it is calculation. Which is exactly the part an app can carry.
The app
What SuisTesJ automates
You note the date of a class; SuisTesJ lays down the seven dates and tells you every morning what to review. Overdue reviews are grouped by course — ten days away is not twenty reviews. Free, offline, no account, on Android and on the web.
Questions
Questions about the method
J method or flashcards — do I have to choose?
No: they answer two different problems. Flashcards (Anki, Quizlet) test the content; the J method decides the calendar — which course to reopen on which day. Many students use both together.
How long does a review take?
Usually 20 to 45 minutes per course: reopen the material, test yourself, do not reread passively. The later the interval, the shorter the review.
Can the intervals be changed?
Yes. The exact values are not magic — it is the growth of the gaps that produces the spacing effect. The default scale is a good start; tighten it before a demanding exam or lighten it for an easier subject.
I am starting mid-semester?
Count the days since you learned each course and resume at the next milestone not yet passed: a course learned ten days ago resumes at J14. No need to catch up on missed milestones — the next one is what counts.