One of the strengths of active learning is the potential for helping students bridge the gap between a library of facts they must memorize and a conceptual understanding how those facts fit into a working biological system, like a neuron generating an action potential. I do not have a magical formula for creating active learning exercises that morph students’ understanding of a concept from a “mental fact library” to a “mental IMAX.” But, I will share three principles I use to help me avoid some common mistakes that can reduce the effectiveness of active learning exercises.