What is Spaced repetition?
Spaced repetition is a learning technique that schedules reviews of each item at increasing intervals. An item answered correctly comes back after a longer gap; one answered wrongly comes back soon. Reviewing just before forgetting strengthens long-term memory more than repeated study in one session, so people retain more for the same time spent.
How Personal Academy handles it
Personal Academy schedules daily review cards with FSRS-5, tracking stability and difficulty per card, on the learner review page on the Advanced plan.
A worked example
Suppose a 300-person medical device company trains its sales team on product specifications. After the course, each fact becomes a review card. A rep who answers a card correctly sees it again in a few days, then a couple of weeks, then longer. A card they miss returns the next day. Each rep spends a few minutes a day on cards, focused on the facts they find hardest.
In 1885 Hermann Ebbinghaus measured how quickly he forgot lists of nonsense syllables and described what became known as the forgetting curve: memory drops quickly after learning, then more slowly. He also found that relearning took less effort each time and that spreading practice out helped retention. Later research confirmed this spacing effect across many kinds of material.
Spaced repetition turns the spacing effect into a schedule. Instead of reviewing everything equally, each item gets its own interval based on how well the learner knows it. Correct answers lengthen the interval; mistakes shorten it. Over time, well-known items appear rarely, and effort is spent where it is needed.
The technique works best combined with retrieval practice. Seeing a question and recalling the answer before checking strengthens memory more than rereading. Review cards, flashcards and short questions are the usual format.
Early systems used fixed boxes, such as the Leitner system with physical cards moving between boxes reviewed at different frequencies. Software then made per-item scheduling possible. SuperMemo introduced algorithms that adjust intervals using an ease factor per item, and modern schedulers such as FSRS model memory more directly using stability and difficulty.
In workplace learning, spaced repetition is useful for facts and procedures that people must recall without looking them up: product details, safety rules, medical knowledge, regulations and terminology. It is less useful for skills that need complex practice. Short daily sessions fit easily into a working day, especially when delivered as cards on a phone or in chat. Consistency matters more than session length.