Too Long; Didn't Read
The Yak Tack app is a simple app that helps people remember words. It's based on the Fibonacci Sequence, which starts as 1, 2, 3, 5, 8, 13, 21, and 34. With each successful test, the repetition interval expands, and with each unsuccessful test, we tighten the interval. We reduced the tack duration from 34 to 13 days, and we test people more frequently than we used to. The algorithm is based on Sebastian Leitner’s system, which was developed in the 1970s. It gives us the adaptation we were looking for.