1. The study of Ebbinghaus (1885):Ebbinghaus (1885): The Forgetting Curve Contributor© POSbase 2003 Hermann Ebbinghaus (1850-1902) was the first scholar who conducted experiments about memory, especially forgetting. He claimed that exact scientific research into memory can be done, in the same manner and with the same exactness as biological or chemical phenomena can be examined.memoryforgetting

2. The Forgetting Curve © POSbase 2003 Ebbinghaus conducted self-experiments. This something done rarely nowadays because experimenters can influence the results if they know the hypothesis (experimenter-expectancy effect). However, the findings of Ebbinghaus have been confirmed even if the participants in the experiments did not what the purpose of the experiment was.

3. Time 0% 100% 50% % Retention 0% 100% 50% Time % Retention Ebbinghaus was interested in the question: Is forgetting a linear or a non-linear process?forgetting The Forgetting Curve © POSbase 2003

4. The Forgetting Curve © POSbase 2003 Ebbinghaus learned a list of meaningless syllables of the form consonant -- vocal – consonant, until he could reproduce the list at heart. Such syllables are not similar to everyday materials. Example: ZUV; XER; GUB; LIW; SAB; QOR; DAF; HUX etc.

5. The Forgetting Curve © POSbase 2003 He measured how long it took to learn the list of syllables. After different time intervalls – e.g., one hour, one day, two days – he relearned the same syllable list once again. He measured the time it took to relearn the list and then calculated how much time he saved at relearning, in %.

6. The Forgetting Curve © POSbase 2003 Ebbinghaus found a logarithmic curve (x-axis categorical):

7. The Forgetting Curve © POSbase 2003 And here the same curve (x-axis true units):

8. The Forgetting Curve © POSbase 2003 The forgetting curve has been replicated many time and with different materials (e.g., Bahrick & Phelps, 1987; McKenna & Glendon, 1985).McKenna & Glendon, 1985 Why do we forget? Some theorists thought that forgetting is due to trace decay whereas others argued that forgetting is due to interference. forgettingtrace decayinterference