A little History: Hermann Ebbinghaus

Hermann Ebbinghaus (1850-1909) made one of the classic contributions to research in experimental psychology (Fancher, 1996, p. 181). He studied the amount of time it took in studying material to see how long it took to remember it very well. Ebbinghaus created nonsense syllables that he did memorize in his experiments. When learned perfectly, he investigated the retention time for a measure of the strength of memory. Everytime he learned anew he needed shorter time for it as before. This was thought to be the strenght of memory.