Forgetting was first studied in detail by Hermann Ebbinghaus (1885/1913). He carried out numerous studies with himself as the only participant. Ebbinghaus initially learned a list of nonsense syllables having little or no meaning. At various intervals thereafter, he recalled as many of the nonsense syllables as possible. He then re-learned the list. His basic measure of forgetting was the savings method, which involved seeing the reduction or saving in the number of trials during re-learning compared to original learning. Forgetting was very rapid over the first hour or so after learning, with the rate of forgetting slowing considerably thereafter (see Figure 6.12). These findings suggest that the forgetting function is approximately logarithmic.
It is often believed that forgetting is a bad thing, and that we should do everything we can to reduce forgetting. This belief is not altogether correct. We often need to update our knowledge, and it is actually helpful to forget the previous state of affairs. For example, when driving you might find it hard to remember the speed limit applying to the area through which you are driving if you had a clear recollection of different speed limits during earlier parts of the drive.