Hermann Ebbinghaus: Biography and Studies

Hermann Ebbinghaus: Biography and Studies

Hermann Ebbinghaus was born on January 24, 1850, to Lutheran merchants in Barmen, Germany. At the age of 17, he entered the University of Bonn, where he developed an avid interest in philosophy. However, his studies were temporarily interrupted in 1870 at the outbreak of the Franco-Prussian War, when he enlisted in the Prussian army. After the Franco-Prussian War he continued his philosophical studies at Bonn, completing a dissertation on Eduard von Hartmann's Philosophy of the Unconscious, and received his doctorate in 1873.

In psychology Ebbinghaus found his own way. None of his instructors determined in any marked way the direction of his thinking. A major influence, however, was the combination of philosophical and scientific points of view he found in Gustav Theodor Fechner. He acknowledged his debt in the systematic treatise Die Grundzьge der Psychologie, which he dedicated to Fechner. Ebbinghaus was an unusually good lecturer. His buoyancy and humor, together with the unusual clarity and ease of his presentation, assured him of large audiences. Another valuable trait was his Jamesian tolerance, which led him as editor to publish widely diverse opinions, a policy vital to a young science.

In 1885 a monograph from the pen of this young psychologist opened a new vista on experimentation. Published in German as Ьber das Gedchtnis and eventually translated into English as Memory. A Contribution to Experimental Psychology, this monograph marked the beginning of programmatic experimental research on higher mental processes. Using himself as a subject, gathering data for over a year, 1879-1880, and then replicating the entire procedure, 1883-1884, before publishing. In order to proceed with his research, Ebbinghaus had first to invent stimulus materials. These needed to be relatively simple, neutral as to meaning, and homogeneous. They needed to be available in large numbers and to allow quantitative manipulation of the amount of material to be retained. In answer to these needs, Ebbinghaus hit upon the idea of a nonsense syllable. As he described it: Out of the simple consonants of the alphabet and our eleven vowels and diphthongs all possible syllables of a certain sort were constructed, a vowel sound being placed between two consonants. These syllables, about 2,300 in number, were mixed together and then drawn out by chance and used to construct series of different lengths, several of which each time formed the material for a test.

Next Ebbinghaus had to develop novel methods for controlling the degree of learning and measuring the amount of retention. At first glance, it would seem that the most obvious method for controlling learning would have been to standardize the number of learning trials. The problem with this method, however, is that the degree to which any given material is learned in a fixed number of trials may vary as a function of the material or the mental state. For example, the attention or fatigue of the learner. To circumvent this limitation and assure that material was learned to approximately the same degree from test to test, Ebbinghaus introduced the method of learning to criterion. In learning to criterion, the subject repeated the material as many times as was necessary to reach an a priori, known beforehand, level of accuracy. Basically being able to reproduce the material perfectly. Measuring the amount of retention also presented Ebbinghaus with a puzzle. Because it is influenced by whole host of factors, conscious recall of material can vary from moment to moment even when the material has been well learned; worse yet, material may not be available to conscious recall at all even though it has been retained to some degree. To avoid this problem, Ebbinghaus invented the “savings method.” Subtracting the number of repetitions required to relearn material to a criterion from the number originally required to learn the material to the same criterion provided an index of retention that was independent of whether the material could be consciously recalled.

With these methods, Ebbinghaus obtained a remarkable set of results. He was the first to describe the shape of the learning curve. He reported that the time required to memorize an average nonsense