Spacing Effect
Older news items (pre-2010) brought over from the old website
The smart way to study
A large internet study has clarified the optimal timing for spacing out your learning. The very systematic study found much larger benefits to spacing your review of material than has been seen in earlier research when shorter intervals have been used. Given a fixed amount of study time, the optimal gap improved recall by 64% and recognition by 26%. Basically, the study found that if you want to remember just for a week, the optimal gap was one day; for remembering for a month, it was 11 days; for 2 months (70 days) it was 3 weeks, and similarly for remembering for a year. Extrapolating, it seems likely that if you’re wanting to remember information for several years, you should review it over several months. (You can read more about this study in my article on the most effective way of spacing your learning).
http://www.eurekalert.org/pub_releases/2008-11/uoc--tsw111808.php
Cramming doesn't work in the long term
Thinking back on how much you remember from your schooldays, it’s apparent to most of us that despite all the time spent in school, we’ve forgotten most of what we learned. A new study points to what we were doing wrong. The study looked at overlearning, which is the term for continuing to study after you’ve apparently learned it. Students went through a list of new words either five times (getting a perfect score no more than once) or ten times (getting it perfect at least three times). A week later, students who did the extra drilling performed better when tested, but four weeks later there was no difference. The results suggest that overlearning in a single session is wasted effort. However, when the material was studied in two separate sessions, and the break between sessions was at least a month, students did much better. Although the experiments involved rote learning, the researchers have also found similar effects with more abstract learning, like math.
http://www.eurekalert.org/pub_releases/2007-08/afps-bts082907.php
Practicing skills in concentrated blocks not the most efficient way
While practicing several different skills in separate, concentrated blocks leads to better performance during practice, it appears that this approach is not the best method of learning for long-term retention. The temporary improvement in performance that results from blocked practice hinders learning because it allows people to overestimate how well they have learned a skill. For long-term retention, it appears that contextual-interference practice (practicing skills that are mixed with other tasks) results in better learning. This may be because such practice requires people to repeatedly retrieve the motor program corresponding to each task (repeated retrieval is a major factor in making stored memories easier to access). Such practice also requires the person to differentiate the skills in terms of their similarities and differences, which may be assumed to result in a better mental conceptualization of those skills. The fact that blocked practice leads to better short-term performance but poorer long-term learning "has great potential to fool teachers, trainers and instructors as well as students and trainees themselves."