Friday, March 13, 2009

Forgetting and Memory: Forgetting is sometimes helpful

On Tuesday I posted on Jinriki about a documentary that I had seen about Steiner Education and Biodynamic farming. On that same video was a theory of education espoused by Steiner and his adherents which stated that after information is introduced in class it is not repeated until some time later, because, "forgetting is important."

I was curious about this concept that forgetting is important. Is it true that our memories are improved by forgetting? I did a little reading and found out that for some things, forgetting is important to remembering. There seem to be two factors at work, one is relearning something after it is lost in the process of accessing other information in our heads, and the process of "spacing."

It appears that people, when retrieving information, often cover up other information in the process, and what is covered up is essentially forgotten. Actually it is not gone from the mind, but just covered over by stuff as the other item is pulled out of its slot, this according to a report called, "Accelerated relearning after retrieval-induced forgetting: the benefit of being forgotten," by Storm, Bjork, and Bjork. What was interesting about their findings was that, "items that were relearned benefited more from that relearning if they had previously been forgotten." That means that after we have forgotten as a result of pulling information out of our brains and then relearn what we have forgotten, our memory of that item is stronger than if we had not forgotten it at all.

The second interesting bit of evidence that forgetting is helpful to remembering, is that, just like with Steiner Education, a longer period of time between learning an item once and then practicing it again improves retention. This came out of the magazine Cognitive Science (2005), 559-586, entitled, "Practice and Forgetting Effects on Vocabulary Memory: An Activation-based Model of the Spacing Effect" This article included information on a previous study where subjects were shown a list of Spanish and English words to study and remember. The researchers spaced study sessions of this material at intervals of one day, seven days, and thirty days, and after thirty days the subjects were tested on their retention. The results were that, "final recall was significantly better as spacing between practice sessions was increased, even though the performance during practice was significantly worse with wider spacing. "

That means several things. First, when we learn something we start to forget it as a function of the passage of time, but if we really want to learn that material, we should learn it once, and let "spacing" do its work for about a month. Then when we come back to it after that time and relearn it, it will be much better than trying to remember the same thing everyday or even once per week.

Steiner was right, though I don't know whether some of this research had been done before he developed his teaching methodology or not. Of course none of the articles that I saw referred to Steiner or to research done at the beginning of the 20th Century. In any case, we can say with authority that forgetting is good for learning, or in the words of Storm, Bjork and Bjork, "forgetting is an enabler--rather than a disabler--of future learning."

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