Just as fluency isn't knowing every word in a language, source literacy isn't knowing every source. It is, instead, the ability to interpret from context, to know what to ask, to read the clues, and to use the understanding brought from knowing about other sources. A person fluent in source literacy is able to do this automatically, the way you know a frog is a frog. The cycle of finding and evaluating is where source literacy lives; it is a cycle that, for many students, is endless and dizzying. With increased fluency, that process becomes less explicit and more intuitive, freeing the intellectual and emotional space necessary for high-level analysis. Source illiteracy is a major obstacle students' success as researchers, but because source literacy is usually gained through experience and not instruction, each student's source literacy depends on factors generally outside of teachers' control. One way to take source literacy from the realm of random experience to that of deliberate instruction is for teachers to design planned learning experiences that require students to interact with the source types on that list, and, ideally multiple examples of each type. To bombard learners slowly with sources is taking a tacit and opportunistic approach and making it systematic and explicit.