Your working memory quickly forgets new information. By repeating it, you forget it less quickly. The German psychologist Hermann Ebbinghaus (January 24, 1850 – February 26, 1909) conducted much research on memory during his career. This resulted in 1885, among other things, in the publication of Über das Gedächtnis (loosely translated: On Memory), which he described as a piece about 'the process of learning and forgetting'. Ebbinghaus concluded from his research that people could initially remember newly learned things well, but that over time you forget things. Ebbinghaus also discovered something else important: the speed at which you forget new information. His research showed that you forget the most in the first 20 minutes and that you generally forget a lot in the first 60 minutes. After about one day, the amount you forget levels off, and after about a week, you will hardly forget anything more: an exponential decline. These data resulted in the Forgetting Curve (red line). The speed at which you forget things depends on various factors, such as how complicated something is, how tired you are when you learn it, and how important it is to you. You also forget less important things faster. It can also make a difference whether something is presented as text, visually, or in both ways (see dual coding). What also emerges from Ebbinghaus's research is that you remember information better with repetition: an exponential growth (green line). This emphasizes the importance of spaced learning (see spaced learning). By learning something new and regularly repeating it, you remember it much better than learning everything at once. You should gradually increase the time between learning sessions.
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