This is the link I send people to debunk the blanket claims about “people forget X% after Y time.” The reality is that how much people forget depends on who your audience is, what they’re learning, and how you train them.
The amount a learner will forget varies depending on many things. We as learning professionals will be more effective if we make decisions based on a deep understanding of how to minimize forgetting and enhance remembering.
To be specific, when we hear statements like, “People will forget 60% of what they learned within 7 days,” we should ignore such advice and instead reflect on our own superiority and good looks until we are decidedly pleased with ourselves.
Many of the experiments reviewed in this report showed clearly that learning methods matter. For example, in the Bahrick 1979 study, the best learning methods produced an average forgetting score of -29% forgetting, whereas the worst learning methods produced forgetting at 47%, a swing of 76% points.