I have been around schools my whole life—first as a student and grad student, and for the last 20+ years as a professor. My own experience as a student was that I tended to ramp up my studying for exams as the test approached. I might look over some information a week before the exam, but I was mostly likely to wait until a day or two before the exam to really study in earnest. My observation of students I teach (and my own kids) is that this pattern hasn’t changed much since I was in school.
But, that pattern of study is not really ideal for good long-term learning. One of the cornerstones of memory research is the distinction between massed and distributed practice. Massed practice is when you study all of the information in one burst. Distributed practice is when you spread your study out over time. Keeping the total amount of study time constant, massed practice can help for an exam, but it leads to poor long-term recall of the information. Distributed practice is much better for remembering information over the long-term.
There are several reasons why students might choose to mass their studying right before the exam rather than distributing it over time. They might just not know that distributed studying is better. However, they might also just be busy. Schools often load students up with work, and so it is hard to allocate enough study time in advance of a test, because there is a lot of work to be done.
An interesting paper by Michael Cohen, Veronica Yan, Vered Halamish, and Robert Bjork in the November, 2013 issue of the Journal of Experimental Psychology: Learning, Memory, and Cognition examined how students allocate study time to items to see if they are sensitive to the benefits of distributing their practice.
In one study, college students learned word pairs (like truth-justice). At test, they were going to see the first word and have to produce the second. Participants first saw all of the pairs on the list one at a time. They could study them and then were told that the pair would be worth either one point or five points if they remembered it correctly. Participants were asked to maximize the number of points they got. After seeing the word pair once and studying it, they were given the option to study it again after a short delay or after a longer one. When participants chose the short delay, the word pair was shown again after the initial list was seen completely. Then, a test was given on the items shown after the short delay. Next, there was a brief distractor period, and then the items with the long delay were shown and a test on those items was given.
Overall, students tended to prefer to assign the high-value items to the short delay and the low-value items to the long delay. Despite this preference, they were actually better able to remember the items that they studied with a long delay compared to those with a short delay. So, people were selecting a method to study that actually made their performance worse. The researchers replicated this finding in several studies.
In another study, students were able to allocate study time to a hypothetical test they were going to take in the future. There was a strong tendency to plan for the most study time close to the exam rather than studying more evenly over a long period of time.
Putting all of this together, then, even without any time constraints, students tend to prefer to mass their practice near an exam (cramming) rather than distributing their study time more evenly. As a result, even when students have the opportunity to learn in a more ideal way, they tend to study in ways that will ultimately lead to more forgetting later. That means that educators need to do a better job of helping students to develop habits that get them to even out their study time. It isn’t a matter of studying harder, just studying smarter.