Benedict Carey recounts the history of memory studies and experiments related to forgetting and remembering – nonsense syllables, snippets of poetry, images. It is a history that leads to what is currently called the New Theory of Disuse, or better, Forget to Learn. According to this theory there are two strengths related to memory: storage strength and retrieval strength.
Storage strength is just that, a measure of how well learned something is. It builds up steadily with studying, and more sharply with use. The multiplication table is a good example. It’s drilled into our heads in grade school, and we use it continually through life … Its storage strength is enormous.
By contrast, retrieval strength has to do with accessibility:
Retrieval strength, on the other hand, is a measure of how easily a nugget of information comes to mind. It, too, increases with studying, and with use. Without reinforcement, however, retrieval strength drops off quickly, and its capacity is relatively small (compared to storage). At any given time, we can pull up only a limited number of items in connection with any given cue or reminder.
What studies on the interaction of these two memory strengths indicate is that, depending on the information to be remembered, our storage and retrieval might be strengthened by intentionally spacing our study and our efforts at retrieval. Forgetting (initially) what we’ve learned might actually help us remember it better in the end.
Using memory changes memory – and for the better. Forgetting enables and deepens learning, by filtering out distracting information and by allowing some breakdown that, after reuse, drives retrieval and storage strength higher than they were originally.
Benedict Carey, How We Learn, 36, 37, 40-41.