Spaced repetition, explained for language teachers
“Spaced repetition” is the idea behind apps like Anki and behind most modern vocabulary tools. It sounds technical, but the principle fits in one sentence: review a word just before you would forget it, and each review keeps it longer.
The forgetting curve
In the 1880s, Hermann Ebbinghaus memorised lists of nonsense syllables and tested himself at different delays. He found that forgetting is fast at first and then slows down — the “forgetting curve”. He also found that relearning something is quicker than learning it the first time, and that each review flattens the curve.
Later research confirmed it many times: practice spread over time is remembered much longer than the same practice crammed together.
How a spaced repetition system schedules words
A spaced repetition system keeps, for every word and every learner, a guess of how well that word is known, and plans the next review from it:
- a word the student just learned comes back soon — the next day;
- each time they get it right, the gap grows: a few days, a week, several weeks;
- when they get it wrong, it comes back soon again.
The result: students spend their time on the words they’re about to lose, not on the ones they already know. The classic algorithm, SM-2, dates from the late 1980s; newer ones such as FSRS fit the gaps to each learner’s own history.
What it means for your lessons
Spaced repetition handles when to review. It doesn’t replace what you do in class: explaining, using the words in conversation, correcting. The two work together.
A few practical points:
- New words need context first. A word met in your lesson, with an example, is much easier to schedule than a word met for the first time on a card.
- Keep sessions short. Ten or twenty words at a time, every day, is better than a hundred once a week. Most students will do five minutes; few will do forty.
- Don’t add too many new words at once. Each new word brings future reviews. A steady handful a day keeps the daily load manageable.
- Mix the ways of recalling. Seeing the translation and producing the word, hearing it and picking it, typing it: each strengthens a different side of knowing a word.
The teacher’s part
The scheduling is the easy part for software. The hard part is everything around it: getting the right words to each student after each lesson, with good translations and examples, and noticing who has stopped practising.
That’s the part Tuteo takes care of for independent teachers: send the lesson’s words once, and each student gets them scheduled for review, with games chosen for how well they know each word. You see who is keeping up, and which words they keep missing.