Final answer:
Ebbinghaus used nonsense syllables to study memorization without the influence of prior knowledge. He measured memory retention through the speed of relearning, creating the 'forgetting curve' which shows significant loss of new information within the first 24 hours after learning.
Step-by-step explanation:
Hermann Ebbinghaus used nonsense syllables as the items he studied in his memory experiments because they would not be confusable with existing knowledge or meaningful material, thus allowing the study of pure memorization capabilities. He deliberately wanted to prevent the influence of prior knowledge on the ability to memorize and recall new information. By using syllables that had no inherent meaning or associations, he could better understand how information is learned and forgotten over time.
Ebbinghaus's measure of how much was remembered after some delay interval was how much quicker he could relearn the same list of syllables. If it took less time to memorize the list the second time, this indicated that some memory had been retained. He recorded how much information was lost over time, leading to the creation of the 'forgetting curve' which demonstrated that memory for new information decays rapidly at first, then levels off over time.
Ebbinghaus found that an average person will lose 50% of the memorized information after 20 minutes, and 70% of the information after 24 hours due to storage decay, which is why the forgetting curve is an essential concept in understanding memory retention.