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Desirable Difficulties

Earlier we discussed UCLA Psychologists Elizabeth and Robert Bjork‘s research on learning and forgetting.  They argue that introducing “desirable difficulties” into training is beneficial.  While they seem to slow our short-term performance, they greatly improve long-term learning.  As instructors we want to see our students succeed.  As such we may unwittingly adopt habits that seem to help students in the short-term but actually degrade our student’s overall growth.  It is important not to shy away from short-term “pain” in favor of long-term gain.  In this series we’re looking at each of the Bjork’s desirable difficulties as tools we can use in flight training.  In Part I we looked at a technique called “variation.”  Today we’ll discuss “spacing.”


Spacing means allowing some time to elapse between practice sessions. Concentrating practice of a particular skill (let’s say landings) in a single session will provide great performance improvements.  The Bjork’s argue, however, that those gains will be short-lived and not retained for future use.  Practicing landings a few at a time and then coming back to them later promotes better performance long-term. The Bjork’s have the experimental proof to back this up.  Spacing leads to better training.

How many times have student pilots and instructors spent entire lessons in the traffic pattern?  A better strategy would be to divide up that practice over several different lessons, or even to do a few laps at the beginning of the lesson and a few more at the end.  It sounds counter-intuitive, and many students and instructors claim they get better by doing more landings in a row.  Remember that much of the improvement witnessed after an intense block of practicing one skill set will not persist over time.

Think about the last time you crammed for a test.  How much of the information were you able to recall a week later?  By spacing the practice sessions, you’re working harder to remember the right information and actions.  You’re exercising skills that you haven’t used in a little while.  This extra effort is the secret sauce of learning.  Short-term performance may appear to slow, but so much more of the performance gained will persist long-term.

Sleep On It

Another benefit to spreading training out over time doesn’t come during the practice session, but in the nights in between.  Sleep researcher Matthew Walker describes the learning benefits of a good night’s sleep.  Sleep is when the brain transfers short-term memories into long-term storage, trims extraneous information from the important memories, and mixes new learning with existing knowledge to develop new insights.  After that the short-term working memory is refreshed and ready to take on new learning.  Your ability to learn new information or skills is greatly influenced by the sleep the night before your learning session.  Your ability to retain that information is equally influenced by how you sleep the night after.

I have often told students who were frustrated with their slow progress on landings or some other skill that they’ll go home, get some sleep, and when they come back they will start out performing better than when they left today.  I’ve observed this phenomenon enough times to know it is reliable, but there is science to back up my observations and explain how it works.  Sleep is where the learning we do during the day is fully integrated into our brain.

Train Better

Spacing gets to the heart of an important distinction the Bjork’s draw: performance and learning are two different things.  The strategies that help us learn better might make it appear our performance isn’t improving very quickly.  In fact it is the best way to improve performance in the long-term.

How can you put spacing to work in your training?