Peter Brown, Henry Roediger III and Mark McDaniel in Salon:
Here’s a study that may surprise you. A group of eight-year-olds practiced tossing beanbags into buckets in gym class. Half of the kids tossed into a bucket three feet away. The other half mixed it up by tossing into buckets two feet and four feet away. After twelve weeks of this they were all tested on tossing into a three-foot bucket. The kids who did the best by far were those who’d practiced on two- and four-foot buckets but never on three-foot buckets. Why is this? We will come back to the beanbags, but first a little insight into a widely held myth about how we learn.
Most of us believe that learning is better when you go at something with single-minded purpose: the practice-practice-practice that’s supposed to burn a skill into memory. Faith in focused, repetitive practice of one thing at a time until we’ve got it nailed is pervasive among classroom teachers, athletes, corporate trainers, and students. Researchers call this kind of practice “massed,” and our faith rests in large part on the simple fact that when we do it, we can see it making a difference. Nevertheless, despite what our eyes tell us, this faith is misplaced. If learning can be defined as picking up new knowledge or skills and being able to apply them later, then how quickly you pick something up is only part of the story. Is it still there when you need to use it out in the everyday world? While practicing is vital to learning and memory, studies have shown that practice is far more effective when it’s broken into separate periods of training that are spaced out. The rapid gains produced by massed practice are often evident, but the rapid forgetting that follows is not. Practice that’s spaced out, interleaved with other learning, and varied produces better mastery, longer retention, and more versatility.