One of the best things about online education is the ease with which we can incorporate retrieval practice, also known as the testing effect, into our teaching. This is the well-established cognitive principle that attempting to get information out of memory, as we do when we are taking a test, greatly increases the chances we'll be able to remember that information in the future. To take full advantage of this powerful effect, we need to adopt the somewhat counterintuitive idea that quizzes and tests are parts of teaching and learning rather than something that happens after the teaching is done (Miller, 2011).