Testing Learning And Delivering It: Why Are Both Time Critical? Since Ebbinghaus first developed his theory of the Forgetting Curve in 1885, we have understood that memory degrades, and the approximate rate at which it degrades. But that repetition in the learning process (e.g. active recall) aids knowledge retention. The Ebbinghaus Forgetting Curve model even suggests the frequency of the repetitions to enhance retention. Of course, what Ebbinghaus was actually describing is the degradation of short-term memory and one process…