Proper spacing of lessons can dramatically enhance learning and larger gaps between study sessions result in better recall of facts. Conversely, cramming-regardless of the subject-is not effective in the long haul.
More than 1000 subjects participated in three learning sessions. In the first session, they were taught a set of obscure but true facts, such as "Norway is the European nation that consumes the most spicy Mexican food" and "Rudyard Kipling invented snow golf." The second session was a review of the same facts. The time between the sessions ranged from several minutes to several months. Study time was held constant in all the conditions.
After some further delay, up to about one year, subjects were tested on their recall of the facts. Not surprisingly, when the interval between the second session and the test was increased, memory became worse, reflecting the familiar curve of forgetting. The interesting finding, however, was that increasing the time between the study sessions reduced the rate of forgetting. This reduction in forgetting was very large-sometimes increasing the likelihood that information would be recalled in the final session by 50 per cent.
Published in PsychDigest, vol. 2. no. 11
The results suggest that the optimal amount of time over which learning should take place depends upon how long the information needs to be retained: "If you want to remember information for just a week, it is probably best if study sessions are spaced out over a day or two. On the other hand, if you want to remember information for a year, it is best for learning to be spaced out over about a month."
Extrapolating from the results, the researcher added, "it seems plausible that whenever the goal is for someone to remember information over a lifetime, it is probably best for them to be re-exposed to it over a number of years."
In light of the study, the co-authors write, "it appears no longer premature for psychologists to offer some rough practical guidelines to those who wish to use study time in the most efficient way possible to promote long-term retention."
Cepeda, N.J., Vul, E., Rohrer, D., Wixted, J.T., & Pashler, H. (2008, November). Spacing effects in learning: A temporal ridgeline of optimal retention. Psychological Science, 19(11). 1095-1102. Retrieved January 9, 2009, from Wiley Interscience at http://www3.interscience.wiley.com/journal/121553469/abstract. The full article can be accessed online for $29.95.
Kiderra, I. (2008, November 18). The smart way to study. University of California-San Diego. Retrieved January 6, 2009, from http://ucsdnews.ucsd.edu/newsrel/soc/11-08PashlerPsychScience.asp