Understanding the early teacher pipeline, how many and what types of individuals are pursuing a teaching credential, is critically important. Unfortunately, as Dan Goldhaber and Kris Holden explain, the two national data collections that can be used to explore these areas provide incomplete and sometimes contrasting pictures about the number of people preparing for a teaching career. They describe how data collection could be improved to address this problem and provide a clearer national picture of who is preparing to be tomorrow's teachers.