President Bush's proposal for mandatory public school testing in grades three through eight signals the beginning of a new era in public education, one marked by increased federal involvement in schools and an unprecedented expansion in the role of tests. A business school graduate and self-styled "CEO President," Bush envisions a business model where educators set objectives, measure performance, and hold students and teachers accountable for results. But will the business model work in education? FRONTLINE correspondent John Merrow examines how the quest for higher scores is changing teaching and learning in America.