First one must learn, then one can teach. Right?
So why did a statesman in antiquity once write:“Welcome those whom you yourself can improve. The process is mutual; for men learn while they teach”
Did this man1 know about the biological details of the human brain? Probably not, and yet his idea has proven to be accidentally true. Active learning , as opposed to passive memorising, forces the brain to interact intensely with the information to be learned. On the scale of passive to active, where does teaching fall?
Have you ever tried filling a blank page with all information on a certain topic? Every fact, formula, hint, and pitfall. That is already the definition of active learning. The brain has nothing to fall back on, except itself. Now imagine doing the same but for a page that must be instructive and understandable to another person. It is not possible to fully anticipate the level of knowledge of that other person, nor any possible questions that could come up. Perhaps your notes on this formerly blank page appear clear and logical to yourself, but somebody else may not be able to make heads or tails of it.
So, where does teaching fall on the scale of “passive” to “active”? Entirely in “active”! In fact, it does not get any more “active” than trying to explain something to someone.
When this is done in class, when the student is asked to teach something to learn it, it is sometimes called “Flipped-Classroom”2. In a tutoring setting this can be done regularly when the student is asked to explain, in his own words, what he has just learned to the tutor.