Telling is a time-tested and efficient way to communicate information. Just try to keep the strengths and weaknesses of lecturing in mind. The most effective teaching involves looking to communicate information in inefficient ways — that is, in ways that make students work to understand the information, and not just listen passively. A big benefit of engaging students in active learning is that it reveals — to us and to them — what they don’t yet understand. With lecturing, we can tell them all we want, but whether they’re listening is anyone’s guess.