Most people seem to prefer studying in big chunks of time. Students seem to have a habit of cramming everything into several big study sessions during each semester. This method, however, has been shown to be less effective for long-term learning than spacing out study with short, frequent sessions (known as distributed practice).

Even with less total time practicing, people who learned in shorter stints of studying (spaced more often or over a longer period of time) did just as well as, and usually better than, those who had more study time overall but in spaced in bigger blocks. This is seen with various types of learning, from physical, procedural skills like typing, to things we might learn by memorizing through repetition, such as history and languages.

Why does distributed practice work?

There is no definitive answer yet as to why distributed practice works better than cramming. Some researchers speculate that it has to do with varying environments during the encoding process of memory, which is when the information we take in is converted to a form that can be stored long term. Since the particular environment you learn in can be a cue in retrieval, learning and reviewing information at different times and places will provide the brain with more retrieval cues. Even being in different moods can help, since a person's internal environment also provides cues for retrieval.

Another factor which might explain this occurrence is sleep. Sleep seems to help consolidate the memories of our experiences during the day. REM sleep plays a vital role in procedural memories (which we’re generally not conscious of – e.g., skating skills) and complex, emotional declarative memories. Declarative memories are memories of specific events such as the conversation had with a friend yesterday, and facts, such as the name of the president. Deep sleep (or slow-wave sleep) is particularly important for these types of memories. After new learning of this type, the hippocampus (a structure in the brain crucial for long-term memory) becomes more active during slow-wave sleep, replaying events and stimulating connections between the hippocampus and cortex, where declarative memories are likely stored.

A third reason distributed practice might be better is that it could be strengthening past memories when previously learned material is studied. The more often you bring them to mind, the easier they become to access. It also promotes deeper thinking about what is being learned, offering the opportunity to make connections between this material and other ideas, situations, and contexts which may not have been considered the first time. Research shows that the more “rich” an experience is, the easier the memory will be to recall. Every time a link is made between new learning and old, experience and knowledge are enriched.

So what’s a good length of time to spend studying?

Author and educator Kevin Paul recommends sessions of half an hour or so in his book Study Smarter, Not Harder. That’s enough time to study a topic meaningfully, but not so long that focus is lost and what is being learned is forgotten. After that, he recommends taking a break; a walk or a nap would be good, since both exercise and sleep are good for learning. Changing subjects may also help. The novelty may stimulate and help the learner concentrate again.

Distributed practice is just one way to make studying more productive, but it can make a huge difference in how well a person retains information and how much is retained in the long run. It can be hard to keep good habits with the demands of everyday life, but they can impact the future success of every aspect of life.

About Study Smarter, Not Harder, now in its third edition, is available from our Web store. Written by educator Kevin Paul, it offers many tips for becoming a better student, and is useful for people in high school, university, or anyone who wants to become a more efficient learner.

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