Stats Made Easy

Practical Tools for Effective Experimentation

Sunday, February 15, 2009

How to arrest what’s-his-name’s forgetting curve

I forget how I first heard about the Ebbinghaus Forgetting Curve (it escapes me!) but it describes very well what I’ve observed when teaching statistics – a very rapid loss of knowledge – possibly as fast as 50 percent per day. However, it's been found that by repeated review and practice, details can be remembered for a much longer period of time. That’s why hands-on workshops can be so effective, as opposed to an academic lecture.

For example, I doubt that by noon I’d have been capable of recalling half of what I learned from an 8 AM organic chemistry lecture back in college. Ebbinghaus’s original forgetting curve probably fit my inability to remember chemical formulas. To make matters worse, my notes trailed off every few lines as I nodded off from all the boring details. That was not good, because the chem prof worked completely by lecture – no reference text. There was no chance of getting a ‘re-do’ on any of the presentations – no re-course so to speak (pun intended). Thus my performance on the final exam left much to be desired (at least I passed).

The lesson here is that reviews can be vital for remembering – repetition is the key to recall. Based on recall experiments (for example, the little know fact that Rudyard Kipling invented snow golf), researchers recently discovered the optimal intervals for repeating study sessions. This depends on how long a person wants to remember things. College students hoping to remember information just long enough for the semester-ending final should space study sessions every week apart may be ideal. However, to recall the details a year later a spacing of some months may be far better.

“To put it simply, if you want to know the optimal distribution of your study time, you need to decide how long you wish to remember something.”
-- From Spacing Effects in Learning by Nicholas J. Cepeda, Edward Vul, Doug Rohrer, John T. Wixted, and Harold Pashler

If you are determined to remember stuff, consider investing $35 in a flash-card program called FullRecall that promises to “help you memorize the knowledge for lifelong periods with the minimum time investment.” Its neural network converges on the user’s forgetting curve to schedule reviews just in time –i.e., when one gets close to forgetting a detail they hoped to remember.

PS. When I mentioned this blog on memory to my son, he recalled that a fellow named Pimsleur developed a graduated-interval recall system that’s now used for learning languages. In a 1967 publication titled A Memory Schedule, this Ohio State University professor observed that “the process of forgetting begins at once and proceeds very rapidly. If the student is reminded of the word before he has completely forgotten it, his chances of remembering will increase. After each such recall, it will take him longer and longer to forget the word again. Thus, a small number of recalls, if properly spaced, can bring about retention over a long period."

PPS. By reading the PS above, you just added some length to your recall of how repetition enhances memory. Good for you!


Post a Comment

<< Home