The forgetting curve: why knowledge can fade quickly after a training
The forgetting curve: why knowledge can fade quickly after a training
You've probably experienced it yourself: you learn something new, it seems logical at the time, you still remember it a few days later, and a few weeks after that you suddenly have to think it through again. That phenomenon is often described with the forgetting curve.
What is the forgetting curve?
The forgetting curve describes the relationship between time and how available memories remain. Hermann Ebbinghaus's classic research into forgetting dates back to the nineteenth century, and has since been re-examined and replicated, among others by Murre and Dros (2015). The exact shape of the curve and how well it applies to real learning contexts are more nuanced than many popular graphics suggest: the well-known claim of '90% forgotten after three days' should not be treated as a universal law. How fast someone forgets something depends on the content, prior knowledge, meaning, difficulty, and what happens after learning. The practical principle remains relevant, though: knowledge that is not retrieved again becomes harder to access.
Why does this matter for trainings?
A training is often an intense learning moment, but afterwards the employee returns to the normal work environment. There, new information, new tasks, and new priorities pile up. If the knowledge is barely used again, its availability decreases. That does not mean the knowledge has completely disappeared, but it can become harder to retrieve independently, see also why employees forget so much after a training.
Two principles from learning science are relevant here. Spacing means repetition is spread across different moments instead of happening all at once. Retrieval practice means employees actively try to pull information from memory, instead of re-reading it. Both principles can be used to keep knowledge active after a training, see also how often you should actually repeat knowledge.
Don't think in terms of extra training days
A common mistake is thinking: if knowledge is fading, we need to train more. That is not necessarily true. A better question is how you can reinforce the existing training with short follow-up interventions, for example five minutes a week in the form of a question, scenario, quiz, or short assignment. That spreads the learning process over a longer period instead of concentrating it on one day. This is exactly the mechanism behind Stiqqo: weekly knowledge activation of five minutes that responds directly to this principle.
Conclusion
The forgetting curve is not an exact prediction of how much knowledge an individual employee still has at a given moment; learning is too complex for that. But the underlying problem is relevant: knowledge that is not used or retrieved again can become harder to access. That is why the period after a training deserves structural attention, just like the training day itself.