I was reading about Hermann Ebbinghaus. He became interested in experimental psychology which led him to conduct memory experiments on himself which then resulted in the publication of his book: "Memory: A Contribution to Experimental Psychology" in 1885.
He discovered the forgetting curve and the spacing effect. How did he do so? I'm aware that he had a list of 2300 "nonsense syllables" to memorize but I have no idea what his process was like. Did he play with different intervals for the review of the material? Things like that. Is the process explained in the book?
I'd like to look at the details to see the connection between his work and the now available software employing spaced repetition algorithms.