Comment by cubefox

> If we step back, we realize that this scheduling system (called “SuperMemo-2”) is pretty arbitrary. Where does the rule of 1, 6, 2.5times correct + 1, reset back on failure come from? It turns out it was developed by a college student in 1987 based on his personal experiments. Can’t we do better?

Note that Anki uses (used) such an old algorithm because it derived it from an ancient open source version of SuperMemo, a software which started the spaced repetition trend. Anki just added a usable GUI instead of the convoluted mess that is SuperMemo. Newer versions of SuperMemo improved the algorithm, but they are no longer open source. I wonder how FSRS compares to current iterations of the SuperMemo algorithm.