DOCTOR KATHERINE RAWSON: Students have an immense amount of information that they're expected to learn across several different classes, but coupled with the fact that they have a limited amount of time and energy that they can spend learning the information. So the question is, what is the most effective study strategy for students to use to maximize both of those goals, to be able to learn everything they have to learn, but in the most efficient way possible? And, when I say learn everything they have to learn, ultimately, what we're shooting for is long term learning; a durable learning, acquisition of a knowledge base, and not just transient familiarity with information that then you forget shortly after you've taken an exam. So, that makes the problem even trickier, not only what is an efficient way to learn, but what's an efficient way to learn for the long term?

A common misconception that students have, or a common strategy they report using, at least, is what we refer to as cramming. That is the night before an exam, spend four hours poring over everything, and then walk in, and take your exam the next day. Actually, research suggests that that's not a bad strategy, if you are going to take your exam in a relatively short amount of time right. The problem is it's very, very bad for long term retention. You'll do OK on your exam, but you're not going to remember that information for much beyond that exam.

A better use of your time is to take the same four hours and spread it out. Say, do an hour on four different days. It's the same exact amount of time, but the payoff is huge. The advantage for memory is much greater if you spread that time out across days, rather than doing it all in one fell swoop right before an exam.

WOMAN: The simplest way to explain our research is with respect to a very common technique that students use, namely flashcards. So the basic idea being that you use that cue on the front to try to retrieve the target information, or the definition, from memory, and then, of course, you flip the card over to check to see if what you've remembered is the right answer. Most students will report using their flashcards, going through the stack until they get an item right once. But then the question is, after you get an item right once, what should you do with it? Well most students say, well, I take it out of the stack and I stop studying it. Our research suggests that that's a mistake, that actually it is time well spent keeping items in the stack of flash cards until you've gotten an answer-- until you've correctly recalled an answer from memory at least three times. After that, there appears to be pretty rapidly diminishing benefit of going beyond three, but at least up to three. It's worth your time.

Another question is, well, how many other days should you pick that stack back up? There again, our research right now is suggesting that the answer is at least three more times. So, after your initial study session with a stack of flash cards, yeah, you should-- it's worth your time to pick that stack back up and practice again at least three more days after that first one, and ideally separated by at least a few days each time.

MAN: And The story is that, back in April of 2010, she's a soccer player and a softball player. She headed the ball. And as soon as she headed the ball, she got a headache, felt nauseated, was unsteady on her feet.

SYDNEY URZENDOWSKI: I used to play sports, soccer and softball, at my high school. I'm going to be a senior. To be honest, I don't really remember much anymore.

My freshman year I played soccer and softball. And I don't really remember either of those seasons. So from what my coach said, there is just a hard ball that just came darting at me. I guess I headed it and I scored so that's good. But I don't really remember-- I don't remember anything, actually.

MAN: She came back to the sideline. They decided that they would hold her out and repeat the baseline test that she had. She actually had a concussion baseline test.

They repeated that and found that she didn't do as well. And she did significantly worse, in fact, than she did at her baseline. So that, plus her symptoms, they held her out.

SYDNEY URZENDOWSKI: Red flags just popped up everywhere. So they knew I had a concussion.