One of the biggest insights from brain science has to do with how our memories are made. For conceptual learning, the evidence is clear that it's through the act of retrieval—having to recall something we have learned—that makes learning memorable for the long run.

For example, I could teach you about neuroscience today (reading is certainly one of the ways we learn). I can activate your schemas and you might even have an "aha moment." But if you don't have to retrieve that learning again, it eventually will get dumped from your brain.

Retrieval can occur through a variety of methods such as sharing what you learned with someone else, reflecting on how it relates to a past experience, doing an activity with hands-on application, quizzing yourself on your understanding, and a host of other learning activities. As instructional designers, we can easily build retrievals into our learning events and empower our learners to do that for themselves.

This is what distinguishes great presenters from excellent instructors. Great presenters can create a feel-good experience that activates our schemas and that we thoroughly enjoy. And we will give those presenters or programs high ratings for satisfaction and raving reviews. But if no retrieval occurs, that learning will disappear in the following weeks and months. Sure, people will still say that they loved it, but they won't be able to remember much of what they learned, nor will their behavior change as a result.

Research has shown that it is most effective to get to at least three retrievals. Memory studies have shown that three retrievals yield the best accuracy and retention. Although you can go on to more, the benefit seems to be better at three, so I focus on that number of retrievals in my own learning design. You can certainly build three retrievals into one learning event, but retention will be even more powerful if you add sleep to the mix.