A nearly universal feature of the human body is efficiency. Simply, if we don’t need something, our bodies get rid of it. The brain is no exception. Our memories decay over time. Our brain dumps irrelevant information that it doesn’t need on a regular basis in order to make our thought processes more efficient, streamlined, and focused.

However, this remarkable efficiency of our brain is incredibly frustrating for students. How many times have you been stressed out while preparing for a final exam because you can’t remember all the course objectives and minutia from each PowerPoint or lecture?

The processes by which our brains forget information can be demonstrated visually on the graph as seen in the video below. In academia, this graphic is referred to as the “forgetting curve.” Each vertical line represents a point in time when we potentially review the information learned on day zero. By strategically reviewing information spaced out over time, you train your brain to develop stronger associations. This lengthens the time required for your brain to forget information, thus increasing your ability to retain what you learned! Essentially, your memory grow stronger and the forgetting curve becomes flatter. Let’s flatten that curve!

Anki's power as a learning tool is largely due to applying the spacing effect by way of a carefully designed spaced repetition algorithm that calculates spacing intervals used to schedule reviews of individual cards. We will lovingly refer to spaced repetition as "the algorithm," from this point forward. This enables students to revisit information only when the algorithm anticipates the need for review. True, lasting memorization is essentially guaranteed - as long as we keep up with the reviews scheduled by the algorithm. By allowing Anki to manage our study schedule in an atomic way, i.e., on a per-fact basis, the result is that we study exactly what we need to study, when we need to study it - no more and no less. In other words, no more cramming. No more pulling “all-nighters.” No more panicking before due dates, midterms or even cumulative final exams. No more forgetting!

Spaced repetition is an evidence-based learning technique that is usually performed with flashcards. Newly introduced and more difficult flashcards are shown more frequently while older and less difficult flashcards are shown less frequently in order to exploit the psychological spacing effect.