The Art and Science of Learning Craft  



Herman Ebbinghaus


Hermann Ebbinghaus (January 24, 1850 — February 26, 1909) was a German psychologist who pioneered the experimental study of memory.

He is known for his discovery of the forgetting curve and the spacing effect. He was also the first person to describe the learning curve.

Ebbinghaus in his Pioneering research on memory, was determined to show that higher mental processes are not hidden from view, but instead could be studied using experimentation.

Ebbinghaus knew that prior knowledge affected learning, and people’s understanding of the words, and the easily formable associations between them would interfere with his results.

He thus had to look for something that could be easily memorized but without any previous cognitive “baggage” attached. For these purposes he used something that would later be called “nonsense syllables”. A nonsense syllable is a consonant-vowel-consonant combination, where the consonant does not repeat.

The syllable does not have any prior meaning. BOL (sounds like ‘Ball’) and DOT (already a word) would then not be allowed, but syllables like DAX, BOK, and YAT would all be acceptable. After creating the possible combinations and eliminating the meaning-laden ones, Ebbinghaus wound up with 2,300 resultant syllables.

Once he had his syllables, he would pull out a number of random syllables from a box and then write them down in a notebook. Then, to the regular sound of a metronome, and with the same voice inflection, he would read out the syllables, and attempt to recall them at the end of the procedure.

It is important to note that Ebbinghaus used himself as the only subject, attempting to regulate his daily routine in order to maintain more control over his results.

He may have kept himself as the sole subject not out of convenience or ignorance but rather, because he did not want to subject anyone else to the tedious experiments. One investigation alone required 15,000 recitations.

In 1885, he published his groundbreaking Über das Gedächtnis ("On Memory“), later translated to English as "Memory. A Contribution to Experimental Psychology" in which he described experiments he conducted on himself to describe the processes of learning and forgetting.

Ebbinghaus made several findings that are still relevant and supported to this day. First, arguably his most famous finding is the forgetting curve.  

Ebbinghaus had also documented the serial position effect, which describes how the position of an item in the list affects the likelihood of said item being recalled.

The recency effect refers to the fact that we remember the most recent information better because it is still stored in short-term memory.

The primacy effect is remembering the first items in a list better due to increased rehearsal and commitment to long-term memory.

His other important discovery is that of ‘SAVINGS’ . Savings refers to the amount of information retained in the subconscious even after this information had been completely forgotten (cannot be consciously accessed).

To test this, Ebbinghaus would memorize a list of items until perfect recall and then would not access the list until he could no longer recall any of its items. He then would relearn the list, and compare the new learning curve to the learning curve of his previous memorization of the list.

The second list was generally memorized faster, and this difference between the two learning curves is what Ebbinghaus called “savings”.

Ebbinghaus also described the difference between involuntary and voluntary memory, the former occurring “with apparent spontaneity and without any act of the will” and the latter being brought “into consciousness by an exertion of the will”.

Ebbinghaus’s effect on memory research had been almost immediate. With very few works published on memory in the previous two millennia, Ebbinghaus’s work on memory spurred memory research in the United States in the 1890s, with 32 papers published in 1894 alone.

This research was also coupled with the growing development of mechanized Mnemometers, devices that aided in the recording and studying of memory, which illustrates the progress that was launched from Ebbinghaus’s work.

Noted psychologist William James called the studies “heroic” and said that they were “the single most brilliant investigation in the history of psychology”.

Esward B. Titchener also mentioned that the studies were the greatest undertaking in the topic of memory since Aristotle.

                                                                                   Forgetting Curve