Ebbinghaus & Measures of Forgetting

The video introduces the topic of forgetting and highlights Hermann Ebbinghaus, a German researcher from the late 1800s, as the first to scientifically study how and why we forget. He conducted self-experiments over 20 years, memorizing lists of nonsense words to 100% recall and then measuring how quickly he forgot them.

Ebbinghaus discovered that the speed of forgetting depends on how well material is encoded, deeply processed, and often rehearsed. His forgetting curve illustrates a sharp decrease in recall within the first 20 minutes (down to about 60%), followed by a leveling off, reaching about 35% after 8-9 hours, which then remains relatively stable for months.

Critics point out issues with Ebbinghaus's research, including his use of only one subject (himself), making it more of a case study. Additionally, he used meaningless nonsense words; subsequent research shows that meaningful material is forgotten less swiftly and extensively. Despite these criticisms, his work was foundational for studying forgetting.

The first measure of forgetting is recall, which requires subjects to reproduce information on their own without retrieval cues. This is generally the hardest measure, exemplified by essay questions, fill-in-the-blank questions, or recalling specific facts like a best actor award winner.

The second measure is recognition, which is easier as it only requires identifying previously learned information from a set of options, such as multiple-choice or matching questions. The difficulty of recognition tests can vary based on the number, similarity, and plausibility of the options provided.

The final measure is relearning, which involves memorizing information a second time to determine how much time or practice is saved compared to initial learning. This measure helps quantify the residual memory for previously learned material.