Hermann Ebbinghaus, a 19th Century German psychologist, conducted a series of memory experiments uncovered some alarming statistics about learning retention. On average, we forget up to 90% of what we’ve learned within the first month. Repetition and reinforcement after the initial learning event does help to decrease this, to an extent. Retention is also affected by how meaningful the information is. The more a learner can connect new information with existing knowledge, the greater the retention is over time.
Understanding this gives educators opportunities to create more effective learning environments.