Perhaps the most influential and important leader in the burgeoning field of psychology was the German psychologist/philosopher Hermann Ebbinghaus. Ebbinghaus was without the status and resources to conduct his experiments on memory using a large pool of random subjects. This is much different than the current system where even undergraduate researchers have access to the university subject pool. Instead, he relied on a single participant who was motivated and driven, himself. While conducting studies using an N=1 is problematic, Ebbinghaus was able to document a number of interesting relationships between time, rehearsal, and memory. He noted that the relationship of the amount (e.g., number of syllables) of what he wanted to memorize was not directly linearly related to the length of time/number of repetitions needed to commit it accurately to memory. He also noted the famous curve of forgetting curve, applying sophisticated statistical methods to document how quickly we forget large amounts of information, and that there are diminishing amounts forgotten over time.
One conclusion Ebbinghaus came to after seeing that it was much easier to remember verses from Don Juan than the same number of words without context was that meaning matters. As a result, he came up with a number of nonsense syllables used to study memory free from contextual associations that may aid memory storage. Ebbinghaus was both lauded and criticized for this experimental technique, with Titchener claiming that he “tended to place the emphasis upon the organism rather than upon the mind” (Titchener, 1910, p. 414). His influence is still seen in the field, as applying the principles of memory garnered from his studies, has allowed for a greater understanding of the development of a variety of memory processes. We have come to understand that memory is made up of several interrelated processes, each of which work on their own unique developmental trajectory.