Hermann Ebbinghaus - Research On Memory

Research On Memory

Ebbinghaus was determined to show that higher mental processes could actually be studied using experimentation, which was in opposition in the popular held thought of the time. To control for most potentially confounding variables, Ebbinghaus wanted to use simple acoustic encoding and maintenance rehearsal for which a list of words could have been used. As learning would be affected by prior knowledge and understanding, he needed something that could be easily memorized but which had no prior cognitive associations. Easily formable associations with regular words would interfere with his results, so he used items that would later be called “nonsense syllables” (also known as the CVC trigram). A nonsense syllable is a consonant-vowel-consonant combination, where the consonant does not repeat and the syllable does not have prior meaning. BOL (sounds like ‘Ball’) and DOT (already a word) would then not be allowed. However, syllables such as DAX, BOK, and YAT would all be acceptable (though Ebbinghaus left no examples) . After eliminating the meaning-laden syllables, Ebbinghaus ended up with 2,300 resultant syllables. Once he had created his collection of 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. One investigation alone required 15,000 recitations.

It was later determined that humans impose meaning even on nonsense syllables to make them more meaningful. The nonsense syllable PED (which is the first three letters of the word ‘pedal’) turns out to be less nonsensical than a syllable such as KOJ; the syllables are said to differ in association value. It appears that Ebbinghaus recognized this, and only referred to the strings of syllables as “nonsense” in that the syllables might less likely have a specific meaning and that no attempt to make associations with them for easier retrieval.